FLASH SONAR PROGRAM:  learning a new way to see




Daniel Kish, M.A., M.A., COMS, NOMC



Copyright 2013




World Access for the Blind



[This document incorporates materials from a document written by Daniel Kish and Hannah Bleier, M.A., COMS. Although this program in practice has been found very successful, the documentation of this program is still under development. Please forgive the rough edges.]









                A. Why the term FlashSonar?


                B. This program is not yet complete.


                C. This program is based loosely on sequenced skills development.


                D. This program is in no way intended to constitute a complete set of activities or skills


                E. These exercises and protocols are intended to activate the brain's auditory imaging process.






                A. Introduction:


                B. Sonar as a Language


                C. Feature and Scene Analysis


                                1. Location


                                2. Dimension


                                3. Depth of structure


                D. What is Detectable?


                                1. Target Distinction


                                2. Environmental Variables


                                3. Perceptual Variables


                E. Applications of sonar:  The applicability of sonar falls into two major categories - orientation and targeting sonar.




                A. Introduction: There are two kinds of sonar - passive and active.


                B. Social appropriateness of clicking


                C. The active sonar call is the basis of the FlashSonar approach.


                D. Optimization of call


                E. Types of Tongue Clicks


                F. Students who use echoes are often unaware that they are doing so.


                G. Handheld clickers


                H. Signals for very beginning exercises






                A. Neural Activation of External Mapping.


                B. Observation


                C. Tips for Teaching Tongue clicks


                D. We believe the brain learns to see by using systematic stimulus differentiation.


                E. Stimulus Sensitization: helping students to "sensitize" to subtle stimuli


                                1. Noticing Strong Echoes


                                2. Bottle exercises


                                3. The phase effect


                                4. Stimulus Target Presentation


                                                a. Sample Exercises


                                                b. Special Considerations


                F. Stimulus Clarification: When students are unable to register or describe a stimulus consistently, it may be that the stimulus needs to be clarified.


                                1. Representation


                                2. Intensification


                                3. Elumination


                G. Stimulus Comparison: It may help to compare directly one stimulus with another.


                H. Stimulus Association: the conceptual version of stimulus comparison.


                I. Stimulus Shift: is used by psycho-physicists to teach a student to register and respond to one stimulus by substituting a more powerful stimulus, then fading that stimulus gradually so that perception of the subtler stimulus builds


                J. Attention Stabilization




                A. Maintaining various facing relative to a flat surface


                B. Orienting to and moving toward an object


                C. Alcove and interior corner location


                D. Tracking Course Boundaries


                E. Centering


                F. Circling










                A. Street crossing


                B. Crossing a parking lot


                C. Self Orientation








                A. Cane users


                B. Partial Vision


                                1. Diffused Occlusion


                                2. A World of Color


                                3. Occlude the Instructor


                                4. Darkened Environments


                C. Recently blind Adults


                D. Congenitally blind kids


                                1. Directed Reaching


                                2. Walking and Cruising


                                3. Infant Scaffording


                E. Working with very young children


                                1. Find the box


                                2.  Stimulate the child's interest in container play. XVI. Self Exercises for Stimulating the Sonar Perception


                                3.  Auditory Space Recognition.


                                4.  Stimulate interest in crawling into or under things.


                                5. Hide and seek.


                                6. Audified Ball play.


                                7. Explorer.


                                8. Counting.


                                9. One student liked to ice skate.







Before we begin, we'd like to present an excerpt from a letter submitted to a blind people's listserve by a parent whose young son received services from us. Among other things, this letter speaks to the ease and acceptance of using FlashSonar. This letter is presented in its entirety at:



"My youngest son, Justin, totally blind, is five ... we introduced Justin to a white cane when he was 18 months old, ... he ... processes the information he gains from it very effectively.


"Justin is a very active, outgoing fellow who loves socializing and sports of any kind. ... the work [Daniel] has done with Justin has had tremendous results. ... Walls are easy for Justin to hear. He has moved on to identify parked cars, store displays, other solid objects like newspaper boxes, bushes, and more - all with the click of his tongue. ... if I ask Justin to go and find a ... solid object that doesn't make noise, he will click his tongue, and ... set off in that direction. As he nears it, he will actually pick up speed and become more confident ... He can then stop short of it ... The delight on his face when ... he discovers what he has found is unparalleled. ... The other day my husband asked Justin to tell him when the type of fence changed along the street ... Clicking his tongue, Justin could tell him when the fence changed from brick to wrought iron ...


"we had already seen Justin using echolocation on his own as a toddler. ... I'm not sure how much Justin knew what he was doing, or how much further he would have went with it. I know that I have heard a lot of blind adults say that they use echolocation to some degree, ... But in Justin's case, with structured training his potential in this area is being drawn out and he is learning to use echolocation more effectively than he would have otherwise. ...


"We, like any parents, want the best for our son. We want him to be as independent and free as he can be. To give him that, we want him to have access to all the options, so that he knows what is possible and can make his own choices. ... Echolocation training is most definitely helping to accomplish that goal. ... I strive to give my child access to all of the resources I can to help him become who he wants to be. This is one such resource. ...


"10 years ago it was unheard of to put a cane in the hand of a toddler. Our toddler is one little boy who has benefited hugely from ... one at such a young age. How many people ten years ago, and even now for that matter, would have told me not to give my son a cane? Is the same thing true to some extent of echolocation? Or are we open-minded enough to explore the idea deeply enough to see if, just maybe, this is a relatively untapped area with tremendous potential? ...


"probably my greatest strength with my son is my ability to teach him social skills. I have a very strong interest in this area, and it shows in who Justin is becoming. He is extremely well spoken, ... very outgoing, confident, and well-liked by his friends and classmates. ... a tongue click ... is hardly noticeable. In fact, unless you were listening specifically for it, I don't know that you would notice it. Ok, well if you are blind you almost surely would, but I am commenting as a sighted person. it is hardly noticeable at all. ... the tongue click in no way resembles a blindism or mannerism. ... Today Justin does not exhibit any mannerisms ... here is something positive that it does do. It keeps the head up nicely, because when you click to scan your environment you lift your head up instead of hanging it down ....


"what does draw people's attention to my son is his cane, more than anything else. Since he first started using it at 18 months, people tend to watch us wherever we go. ... His cane by far draws more attention than a tongue click ever would. ... that is the reality of it from our own experience. ... Tricia"


We will add that Justin began losing his hearing bilaterally by the age of six.  He has been aided in both ears ever since. He is 13 years old at the time of this writing. Justin has applied focused training in FlashSonar and other perceptual mobility skills to develop his spatial process to a high degree despite his hearing impairment. Moreover, we feel and Justin would concur, that focused training in FlashSonar has resulted in a generalized improvement across a wide range of auditory functioning. For instance, Justin's complex, lighted intersection crossing abilities are on or above par relative to his age peers without hearing impairment. Given his hearing impairment especially, Justin most certainly evidences benefit from the use of a focused tongue click to provide him with enhanced imaging. Without it, the resulting echo intensity just isn't consistently strong enough for him to construct sufficiently detailed and robust images.




                A. Why the term FlashSonar?


                Many echolocaters have learned to use echoes to advantage, and many instructors have developed some ways of teaching echo skills. However, we have found that the application and instruction of echolocation typically falls short of its actual capacity. Echolocation has come to be identified with relatively rudimentary abilities, such as detecting openings, building lines, sizes and maybe shapes of rooms, whether we're walking straight along a pathway, whether something is over head, and whether an object might be in our way. However, the actual potential of echolocation ranges far beyond this, and we are consistently able to achieve these advanced results through our method of instruction as outlined in this program. Thus, we have coined the term FlashSonar to distinguish our approach, and the broad purposes to which it can be applied, such as auditory scene analysis, identification and recognition of complex environmental features, perception of small objects and fine details, and high speed movement (running or biking speeds).


                The use of sonar can be consistently fostered to a far greater degree than has been traditionally supposed or consistently demonstrated. Some have expressed that only a select few can learn the skill to a heightened capacity, but we have found this to be untrue. We have found notable success with most students of all ages and backgrounds including students with autism, hearing loss, and cognitive impairments. We have also successfully taught very young toddlers. What is sometimes taught and often used is only preliminary to the more advanced degree, scope, and complexity of perception that echolocation can afford.


                Furthermore, no systematic, comprehensive training programs have been documented to our knowledge that support and facilitate the development of this valuable way of seeing.


                The term "FlashSonar" differentiates the strategic use of advanced, active sonar from the more commonly applied forms of echolocation. This was partly inspired by the fact that, in all of nature, humans are the only animals to our knowledge that tend to rely on more passive or incidental forms of sonar. Active sonar, which is about to be discussed, is believed to be the standard form of application throughout nature, and in almost all technical applications.



                Another issue with regard to the focused development and use of FlashSonar concerns the activation of the imaging system in the brain. We now know that active echolocation by use of an active signal can reliably elicit bold images in the brain that are closely analogous to visual images. While we do not yet know all of the aspects of how this process works, we do know that the brain requires a certain strength of stimulus in order to elicit enough neural impulses to produce a conscious stimulus. It is our observation from work with hundreds of students and thousands of instructors, including some former students of NOMC'S and a few NOMC instructors, that a lack of focused development in active echolocation does not appear to be sufficient to activate the imaging system to the degree that is possible. This is a supposition based largely on behavioral evidence.


                B. This program is not yet complete.


                It is still evolving, but it provides a firm foundation in facilitating the perceptual adaptation process with regard to FlashSonar.


                C. This program is based loosely on sequenced skills development.


                In-keeping with a modern developmental psychology perspective, we don't fully subscribe to the sequenced approach. While rough developmental milestones and sequences may exist, they are heavily dependent on personal, social, and environmental factors. This is particularly true for blind individuals whose developmental sequencing is even looser than that of the general population. This is especially true when considering that a much higher percentage of the blind population is faced with the challenge of additional involvements. Given this, we have found that the application of a sequenced skills curriculum often misses the mark. We would say that development and learning are only partly driven by developmental sequences that may be more or less hard wired, and also largely driven by what we may call "salience." We are driven to learn and grow by what is salient to our interest, survival, and attainment of resources. For example, children understand fractions long before they are formally taught the arithmetic operations as demonstrated by their awareness of equity when it comes to cutting pie and pizza. They often understand money long before they are able to do percents, and all of us understand time (base 12 or base 24) before we are even introduced to the concept of bases. Blind children are often observed to excel well beyond their sighted peers at certain skills, such as swimming, climbing, music, roughhousing, and auditory processing, and research has shown them to develop abstract language well ahead of "schedule," as these various skills may be more salient to their style of exploring and understanding the world. Thus, we have been unable to develop a step by step, sequenced curriculum that we feel properly supports the perceptual adaptation process. This program is based more on salience than sequence. The instructor should be warned not to try to impose this curriculum on a student in a sequenced, prescripted manner, but should first strive to understand the student's perceptual and environmental interaction style.


                The key above all, is to maintain a student's interest in the tasks, and motivation to learn. Some students may seem averse to self directed travel, but it is vital that this aversion be replaced by a desire to explore and discover, even if assisted to do so. Helping the student maintain interest and motivation is worth far more than the most carefully designed hierarchy of tasks. In our experience, once the student's interest is lost it doesn't much matter what we do.


                D. This program is in no way intended to constitute a complete set of activities or skills.


                The activities included are selected to represent broadly the principal types of interactions that people may have with the environment. They are also intended to provide focused opportunities to practice developing certain specific skills. These activities must be adjusted or modified according to student need and environmental determinants. It will also be necessary to add other activities according to need. The sequence suggested here is only a very general guide, and will not apply to every student in all situations. In fact, it really should not be thought of as a "sequence." However, generally speaking, it is easier to learn to perceive one target before many targets, simple targets before complex targets, and targets from a stationary perspective before moving. Nonetheless, there are notable exceptions. Some students, for instance, can't make head or tales out of the simple panel exercises before they've been able to experience it walking around in the real environment.


                You can make a sonar exercise out of just about any activity. Many kids love to play around with a tetherball. We would have them find tetherball poles with the incentive that one of the poles had a tetherball. They loved it. Other times it was "take me to the things you like to play on." These might be monkey bars, swings, the slide, a merry-go-round, etc., that they were encouraged to find with FlashSonar. While it is often surprising what blind kids can do and learn, we were also surprised by what our students didn't know, like "how do you get to the jungle-gym from the slide." Blind kids who just follow the sighted kids all the time may not know. With one kid, we would pick him up and spin him around in a toy airplane to get him totally disoriented. He had a blast. Then we would practice finding the slide from where he was set down. He loved it!



                E. These exercises and protocols are intended to activate the brain's auditory imaging process.


                It's analogous to the way we teach anything in a discovery model. We present the stimulus to the student in such a way the student can fully appreciate it. Then, once the stimulus is understood, we facilitate a student's perceptual and interactive discovery of subtler and more complex stimuli. We believe that the key to activating the greatest adaptation to the perception and use of these stimuli lies in self directed exposure to quality stimuli in representative environments and situations. That's really what this program is all about.




The ability to direct our interactions with the environment is connected to the perceptual imaging system. The brain creates images through the perceptual system to represent everything we experience. The quality of these images impacts how we interact with the environment. The brain uses perception to gather information which feeds comprehension, which further improves our interaction.


Perception lies at the center of our ability to direct ourselves toward achievement. Other processes, such as comprehension, psychology, and mutual social engagement, are critical, but information supports the development and utility of all other neural mechanisms underlying self direction. Without information about the world, what is their to comprehend, who is their to engage socially and by what means, and with whom and how do we relate psychologically? We establish and execute intent by drawing meaning from what our senses register. The more information we can access, the more adaptive and more varied is our interaction with the world.


Accordingly humans have developed integrated, adaptive brain function that anticipates information through the perceptual process in two principal modes relative to movement - referencing and preview. Referencing refers to recognizing and discriminating elements around us which allows us to set a physical goal toward which movement can be directed, and to maintain orientation with respect to surrounding elements. Preview refers to awareness of elements and their layout in advance of our position. This allows us to direct our course efficiently, safely, and gracefully. Both these modes of gathering information can be divided into near, intermediate, and far.


We use this information about what lies ahead and around us to govern interaction.  Without this information, the purposeful flow of movement is disrupted. We struggle to apply other processes to interact with the environment in a manner that is adaptive and mutually meaningful to self and others. Broadly speaking, this usually disrupts the development of grace and confidence to direct ourselves toward achievement.


Neural development depends largely on self directed discovery based interaction with our environment. Directing our own interactions, rather than passively responding to others' directives, engages the nervous system most completely; it matures best by understanding its relationship to the world through self initiated, self directed exploration. A strong perceptual process helps develop strong intentional action.


A robust operational image is rich in character derived from multiple data streams of sensory experience and ideas. When vision is compromised, the brain naturally works to maintain image integrity by optimizing perception and self directed discovery to heighten the quality of meaningful information gathered through all senses. The compromised ability to see with eyes need not compromise achievement when the brain learns to "see" with an in tact and heightened perceptual imaging system. Thus, self directed, intentional interaction greatly supports brain development, especially for people with sensory impairments.


Although learning to see with compromised eyesight is natural for the brain, this process is easily disrupted by external forces which impose unnatural conditions of restriction or experiential deficits. Chief among these may be the imposition of surrogate functioning in which the functioning of the student is taken over by external agents. Students with sensory impairments often remain relatively passive while others take over without eliciting the student's self directive input - motoring the student, remote controlling the student with excessive verbal or physical guidance, choosing direction for the student. This can diminish opportunities for self directed interaction which is a key catalyst for many areas of development - especially for the perceptual and psycho-emotional system. Under these conditions, these systems either atrophy or become otherwise disrupted. Poor capacity to mature through self direction compels the development of perception and interaction with the environment through the leadership of others, rather than one's own leadership. Access to the world becomes relegated to and mediated by proxy perceivers which commandeer a degree of autonomy that should develop naturally with support. This can foster a self concept of neediness. Locus of control can become externalized, and achievement capacity is usurped by lack of self efficacy. Or, the child may become extremely demanding and controlling in order to have needs met or desires addressed by others in the absence of their own capacity to do so. This becomes restrictive when assistance is not engaged in a mutual, give and take manner.


This pattern often develops understandably from the need to care for an infant who may have presented very real fragility. The support system may have been compelled to provide every measure of support to ensure the infant's survival. Decisions are made to address the most critical needs, and perspectives and philosophies about the niceties of the future may be put aside by the real and immediate urgencies of the moment. Then, families may not encounter professional support to ease this initially necessary and healthy pattern of dependency into a process more supportive of natural growth toward self direction, even when parents ardently desire this shift.


Two key requirements enable safe, efficient, and intentional movement:  remaining on a chosen course, and avoiding body contact with the environment. The perceptual imaging system naturally endeavors to reference and preview surrounding conditions in order to plan interactions. We establish intent by drawing meaning from what our senses register. When available, FlashSonar and the long cane naturally provide reference and preview information to address these movement requirements.


Although vision seems to be the default for gathering this information, the latest in neural research suggests that, when vision is disrupted, the brain may still anticipate and seek this information. The mechanisms involved in self direction can restore functioning by restoring these modes of information access despite vision loss. For both the blind and sighted brain, it is necessary to foster the brain's capacity to utilize referencing and preview in order to maintain self directive capacity. For sighted people, this happens relatively naturally in sighted society. As visual functioning drops, tactual/kinesthetic and auditory channels must be more intensively stimulated and applied to restore these modes of information access. Touch, hearing, residual vision, and attitude must be respected and supported with perceptual enhancement training from the first steps when patterns of self and intent are first being established.  A self concept of personal achievement must be fostered.  Children must be supported to discover their world without Nervous Nelley's hovering over every move.  Mistakes will happen, but all children, disabled or not, must learn from mistakes.  Use of the senses can be refined with instruction, but most important is that children learn that their senses are tools for achievement.  Professional instructors are the sign posts, but the family is the vehicle to make this happen, and under the right conditions it does happen.


For blind people, hearing can become the dominant sense for conveying spatial information about the world at intermediate distances, and facilitating dynamic interactions with the world. As determined by brain scan research, the capacity of audition to discriminate, recognize, and image multiple events in dynamic space, called scene analysis, is very pronounced. In addition, a wealth of widely publicized anecdotal evidence indicates prodigious capacity. However, the auditory system remains little understood or applied. It can't be emphasized enough that hearing in blind people must be recognized and carefully cultivated for use to improve environmental interaction.


We have found FlashSonar training to be applicable to almost anyone who wants to learn, and who has opportunity for regular practice under challenging circumstances. The perceptual system is not necessarily tied to the communication or cognitive process, so many of these skills can be learned even when cognition or communication is impacted. With students who are low verbal or cognitively delayed, we use a more experiential approach, with less drill and less verbal explanation.



The visual system of the brain is believed to be the only part of the perceptual system that represents the external environment directly within the neural network. Thus, in a very strict sense, the external environment is represented within the neurology in a manner that is believed to be correspondent with the external world. For example, when an objects is presented to the visual field, it activates a distinct part of the brain that corresponds to the position of the item. The auditory system does not activate in this systematic spatial pattern in this way. The tactile system does, but only for stimuli that actually touch the skin, so we do not call this externalization. Only the visual system is known to represent or "map" external space within the brain.



However, it is also known that, under certain circumstances, the visual brain or imaging system can be deployed to externalize the world through nonvisual sensory modalities. We call this the "perceptual imaging process". It is the brain's way of representing its experiences to the conscious mind. We hypothesize that this process requires strong (bold) stimuli and intensive, consistent experiences to activate. Since visual input tends to be bold, and visual experiences tend to be rich and common, the visual system naturally adapts very quickly to externalizing space through vision. However, we think it is possible to deploy the visual system reliably and consistently to externalize the world through nonvisual modalities, provided that these nonvisual sensations and experiences are bold, rich, and consistent in character.


In the case of hearing, we believe that the auditory cortex learns to code the auditory data in some special way having to do with temporal calculations and sequencing before transmitting this data to the the cerebellum for further temporal  processing and application to movement, the visual cortex for spatial processing and imaging, and the cerebrum for comprehension and executive function. Without the temporal coding, I'm not so sure the visual cortex would quite know how to process the auditory data, but that's just our sense. That the auditory data are also processed somehow in the cerebellum is known, and we can only speculate why, but we think it has to do with some kind of pre-anticipation of motor planning and sequencing. In order to interact with the world and discover our way, we involve ourselves in a relatively high amount of movement and motor planning. We also recruit large cerebral processes to comprehend our circumstances, and to connect the dots of nonvisual data.




                A. Introduction:


                Vision and hearing are close cousins in that they both can process reflected waves of energy. Vision processes photons (waves of light) as they travel from their source, bounce off surfaces throughout the environment and enter the eyes. Similarly, the auditory system can process phonons (waves of sound) as they travel from their source, bounce off surfaces and enter the ears. Both systems can extract a great deal of information about the environment by interpreting the complex patterns of reflected energy that they receive. In the case of sound, these waves of reflected energy are called "echoes."


                To get these echoes, specialized sounds called echo or sonar signals are generally sent out. Bio-sonar scientists often refer to these as "sonar calls." These signals or calls travel forth, strike surfaces in the surrounding environment and return. The process is much like using a flashlight. Although sonar is much lower resolution than vision due to the use of much larger wavelengths, the listener can interpret information about surrounding surfaces that the returning echoes carry, much as a sighted creature interprets patterns of returning light. These sonar calls in the form of sound waves actually return to the listener with imprints that correspond to the characteristics of the surfaces from which they bounced. Therefore, the characteristics of surfaces can roughly be extracted from these imprints to construct real, concrete images of space that we call auditory images, that bear a gross resemblance to the spatial characteristics of visual images.


                Blind humans can fill the darkness with dynamic images derived, not from light, but from sound. A blind traveler can perceive multi-dimensional information from distances of many dozens of meters depending on circumstances. Echoes make information available about the nature and arrangement of objects and environmental features such as overhangs, walls, doorways and recesses, poles, ascending curbs and steps, planter boxes, pedestrians, fire hydrants, parked or moving vehicles, trees and other foliage, and much more.


                B. Sonar as a Language:


                Many scientists actually refer to the process of irradiating the environment of sonar calls and interpreting their feedback as "interrogating the environment." Sonar calls are sent out actively for the purpose for soliciting information in a directed, intentional fashion. The environment may be said to respond to these calls with information. We see this process as interactive. The quality and scope of the information returned depends on the quality and delivery of the calls, and the calls are delivered and adjusted depending on the information received. Therefore, we prefer the term "conversing"; echolocaters converse with their environment. Each call essentially makwhs two inquiries, "where are you" and "what are you." As the environment responds, the echolocater may adjust his queries to broad his search, solicit more details, or whatever. He may raise or lower the strength of his call, focus it elsewhere by scanning, increase or decrease its repetition, and so on until the desired image is constructed.


                We also work with students on developing a language to express and convey their experiences both to themselves and to others. Sighted people love to talk about what they see. A rich, visual language has developed that sighted people use to communicate. Thus, sighted people can convey their own images to others by this rich, visual language. Blind people are often left out of this communication process. Society tends not to support development and use of nonvisual descriptors. They may mystify sighted people, or just go misunderstood. For example, when one of our Scottish teenaged students was asked if he was aware of using echolocation (after we had explained what this was), he said (in a delightful Scottish accent we cannot represent here, "Well, I sometimes think I can hear walls, but my mum says that's stupid." We often hear similar stories. So, part of our approach is to help students develop a vocabulary which they can use to communicate their experiences to others in a manner that may be better accepted and understood. We will speak more about this in the next section.


                C. Feature and Scene Analysis:


                Echoes can convey detailed information about the environment according to 3 principal characteristics:


                                1. Location.  This refers to the placement of single and the layout of multipple items - where they are relative to the echolocater and to each other. This can be determined in 360 degrees (up, down, left, right, front, back), although some research has shown that frontal acuity seems strongest. It also refers to the distance of items from the observer.


                                2. Dimension.  This refers to how big items are and their general contour. Here, we are mainly processing the width and height of the item's surfaces through edge detection. Essential, one is taking an outline of the edges of the item or items in question.


                                3. Depth of Structure.  This refers to the characteristics and make up of the items's surfaces - how solid or sparse (density), how hard or soft (reflectivity vs. absorbency), and a gross  sense of rough and smooth (course texture).


                Just by understanding the interrelationships of these qualities, much can be perceived about the nature of an item or multiple items. For example, an item that is tall, narrow, and uniform from bottom to top may be recognized quickly as a pole. An item that is tall, narrow, and solid near the bottom while broadening and becoming more sparse near the top would be a tree. More specific characteristics, such as size, leafiness, or height of the branches can also be determined. Something that is tall, very broad, and solid registers as a wall or building, whereas something solid and broad, yet short in height, perhaps waist high, would register as a retaining wall. Something broad yet sparse in sound would register as a fence. Something short and fairly narrow, a little wider than a person, with a sparse, scattery sound might be a bush, whereas something with a sparse, scattery sound but broad might be a hedge or tightly packed row of bushes. Something that is broad and tall in the middle, yet shorter at either end may be identified as a parked car. The differentiation in the height and degree of slope at either end can identify the front from the back end; typically, the front will be lower, with a more gradual slope up to the roof. Distinguishing between types of vehicles is also possible. A pickup truck, for instance, is usually taller, with a hollow sound reflecting from its bed. An SUV is usually tall and boxy overall, with a distinctly blocky geometry at the rear. And finally, something that starts out close and very low, but recedes into the distance as it gets higher is a set of steps. More or less concentrated scanning may be necessary to make some of these determinations.


                By using this information, a scene can be analyzed and imaged, by perceiving this information and layers of distance and direction. This allows the observer to establish orientation and direct his movement within and through the scene. As with the visual system, this process becomes unconscious.


                D. What is Detectable?


                This varies widely among students and circumstances. The maximum resolution of sonic, unaided, human flash based sonar is about 9 square inches (a circular or squarish target) at about 18 inches distance from the listener with a solid target presented alone in open space under quiet conditions using a sonar signal with primary frequency at about 3 kHz. This figure is general, and is drawn from a synthesis of the literature and our experiences as blind users and teachers at World Access for the Blind. A pole of about an inch diameter can be perceived at about two feet. A fire hydrant may be perceived from several feet away, but not up close unless the student is very short. Likewise, a 4 inch curb is also easier to detect from distances of about 3 to 10 feet, but not too close. A chainlink fence may be detectable at 6 to 10 feet. A parked car may be perceived at 10 or 15 feet; add another 5 feet for a van or truck, another 10 feet for a bus or RVFOR me'. A tree may be detectable from 15 or 20 feet. A large building is detectable for hundreds of feet with a strong sonar signal. While features in terrains such as mounds, large rocks, up-curbs, or mud puddles may be detectable, drop-offs are almost impossible to detect. Low objects such as curbs seem taller than they are from several feet away. These may be difficult to perceive up close. Although echoes are quiet and subtle, echoes from large, hard, nearby objects are extremely pronounced once you know what to listen for. It becomes as ridiculous for blind people to run into a wall as it is for sighted people. Excuses for running into easily detectable things should not be made for blind people anymore than sighted people.


                Sonar struggles most with figure-ground distinction - distinguishing one object or feature from others. Elements tend to blur together - blending small elements with large. Also, high noise levels or wind can mask echoes so that they can be difficult to hear, requiring louder clicks and more scanning.


                There are 4 primary considerations to teaching, using, and evaluating FlashSonar. These are target distinction (how detectable are the targets), environmental variables (noise and clutter), the perceptual factors in the student (hearing issues, presence of vision, attention capacity), and the character of the sonar call and how it is used. Generally, the character and strategy of the sonar call serve to optimize all of these conditions, and this latter consideration will be discussed in another section.


                                1. Target Distinction. Targets that are very narrow, such as a pole, may not bounce back as much sound, and may be more difficult to detect. The more sparse (less dense or solid), the target, such as a fence, the larger it will probably need to be to bounce enough acoustic energy back to a human listener to be detectable and identifiable. Of particular concern with human sonar is figure ground. This concept acoustically is very similar to this same concept as it relates to vision. It has to do with the extent to which the target can be distinguished from its surroundings. Acoustically, we are talking about physical geometry and texture of the target relative to its surroundings. These need to be quite distinct for a target to register to the human audible system, but experience, concentration, and contextual clues can narrow this gap. It's hard to quantify this distinction, but we get an idea of it from the resolution data above. If a target needs to be about 9 square inches to be perceived at a distance of 18 inches from the listener, this gives us a general idea of how distinct a target needs to be in order to be registered, let alone identified. Objects that are too close to each other tend to blur together, with larger, more dense objects predominating. For example, while a person of average man size may be detectable at about 7 feet under normal conditions, that same person at the same distance may vanish if standing next to a wall or large column. However, he might still be detectable against a chainlink fence. We always gage this by ear when working with students. Ground level targets are also an issue, as the presence of the ground, together with the distance from the ears and the relatively poor angle of perspective all tend to blur ground level targets, unless they present a large surface area, or are otherwise quite distinct. A 4 inch high curb may be detectable from 9 or 10 feet, but a park bench might only register at 5 or 6, and a coffee table near a couch might not register at all. Incidentally, this is where children have a huge advantage. Their reduced height has the effect of literally making the whole world larger from the auditory perspective. They can detect shorter objects much more easily than adults whose heads are further above these same objects.


                                2. Environmental Variables. Basically these include factors that increase or decrease target distinction. Noise in the environment will make sonar signals harder to hear, so targets generally need to be bigger or more solid to register, and sonar signals need to be stronger. Reverberation can have a similar effect. This could also include rain and strong wind. With strong wind, it can help to scan left and right repeatedly with the head, or incline the head such that the affect of the wind is minimized. Echoes are subtle and may be easily masked by noise, although FlashSonar can be used to extract images through moderately high noise levels. Clutter or congestion can obscure a target by causing it to blur with other targets that are too close. When teaching students, we try to choose quiet, open spaces, or focus on highly distinct targets until students become more advanced.


                                3. Perceptual Variables. Here, we're talking about things like attention, visual functioning, auditory functioning, familiarity with the environment, and self confidence. We should remember that the three primary determinants for success are motivation, frequent and regular practice under self direction, and application under challenging circumstances.


                                Frequent and passive use of human guide will find FlashSonar more difficult to learn. This is not to say that using human or dog guides in and of itself will disrupt perceptual development, but passive dependence on guidance will. We work on students maintaining active and mutual engagement in the guiding process. Once learned, FlashSonar can be used to allow student more freedom to move around comfortably without a guide when necessary or desired. Or, it can be used in conjunction with a guide to enrich the travel experience by heightening appreciation and awareness of the environment.


                                Echoes are subtle and require one to be able to attend or at least be motivated to hear them.


                                Familiarity usually increases registration. It is always easier to find a target when you know what you're looking for.


                                Broadly speaking, better hearing enables the highest potential for using echoes. However, while high frequencies are required for the perception of small objects and detail on surfaces, most useful sonar skills rely more heavily on mid frequencies. Even if hearing sensitivity is reduced across large portions of the spectrum, effective sonar navigation is often possible. Unilateral hearing loss can make sonar very tricky but not necessarily useless. It is possible to echolocate with hearing aids if the aids do not interfere with the penna.


                                Vigilance is perhaps the most important factor. Because there are many cues that must be analyzed and integrated for successful blind navigation, concentration is often divided among many elements. Since sonar information is relatively subtle, it requires at least a moderate degree of continued concentration for effective use.


                                Finally, it is our experience that congenitally blind students are often already partly adapted to using the auditory system for imaging. However, they are often unaware of it, and their skills are usually rudimentary. They can often express what is around then once the implications of the various stimuli are pointed out, such as solid vs. sparse, but they may not have used this detail to govern their travel. They are often aware of minute stimuli, but often not aware of what it means, or how it relates to them. For example, they may often accurately describe the elements of an object or scene, but not be able to put this information together to form meaning. Once, we had a newly blinded woman participate in a workshop along side two congenitally blind rehab counselors. The congenitally blind participants would say things like, "There's a soft, kind of flattish thing in front of us, with some small, soft things behind it, and a big, hard thing behind it further away." When asked what they were looking at, they sometimes couldn't even guess. Whereas the newly blind woman, though she couldn't sense the elements, could guess accurately what they were once they were described, "It sounds like maybe a fence with some bushes behind it, and maybe a building behind that." The congenitally blind participants were hearing the elements, but not imaging them. The newly blind woman was gaining images from the verbal descriptions. We aim to help students both hear the elements, and gain images based on the elements that are heard.


                E. Applications of sonar:


                The applicability of sonar falls into two major categories - orientation and targeting sonar. Orientation sonar is used to take stock of one's surroundings (analyze the scene), to establish and track one's position within those surroundings, and to navigate through them. Targeting sonar is used to fix one's attention on one or more targets in order to gain information about them, to intercept them, or to avoid them. These two uses of sonar correspond to research and observations made independently in the blindness literature in that mobility has been divided into two similar categories - moving along (requiring maintenance of orientation), and moving toward (requiring location and recognition of chosen targets while negotiating other targets).




                A. Introduction:


                There are two kinds of sonar - passive and active. Passive sonar is reliant on incidental sounds in the environment which elicit incidental reflections. Or, it may involve sounds produced incidentally by the user, such as footsteps or cane taps. Because these are produced by the user but lack some of the characteristics of reproducibility that an organic signal can produce, we refer to these as semi-active. One can use this to gain information about large features or general layout, but one is reliant on incidental noises that will not be ideal for detection of small features or fine discrimination. The images thus extracted are relatively vague. Signals occurring incidentally can take any form or set of characteristics at random, yet signals ideal for sonar applications must contain specific characteristics to optimize them for this purpose.


                Active sonar involves the use of signals produced by the observer. It allows the observer to direct actively a self generated signal into the environment as desired. As discussed earlier, bio-sonar scientists refer to these as "calls". Ideally, the user will have as much control over the call as he would his own speech, in order to adjust it to interact adaptably with any situation. The characteristics under control of the user, according to the latest research, should ideally include intensity, reproducibility (degree of consistency), duration (how long to produce), interval between calls, spectral content (tempre), usability (how easy to produce and control), adaptiveness (user variability), noise immunity (how robust and distinct the call remains in the presence of noise), and directionality (how focused the call can be made and directed). To this, we also add alignment between the emitted signal in the ears. We find in nature that this alignment has invariably evolved to be straightforward, and sonar engineers work very hard to maintain good alignment between emitter and receiver. For the present, only organically produced signals or calls fit these criteria, so we consider these to be the most active, and the most optimal.


                The images produced are relatively sharp in focus and detail. It is like the difference between taking a picture in strictly ambient lighting, or controlling the lighting by use of a "flash" or strategically placed lighting. While esthetic appreciation may favor the natural look at times, no one can argue that photos and video are always clearer and crisper with sharper detail when the scene is brought under the control of the photographer.


                The greater effectiveness of active sonar lies in the brain's control over and familiarity with the signal which allows it to distinguish between the characteristics of the signal it produces from those of the returning signal or echo.  The returning signal is systematically changed by the qualities of whatever object or feature returns it, and these changes carry information about what the signal encounters.  The relative precision of active sonar is why it is used most widely in nature and in technical applications. In submarines, the captain will occasionally tell the sonar technician to "run silent." This means that the sonar technician must turn off the sonar signal and navigate the sub by passive sonar means, or remain very still. The only reason a captain would give this order was if the sub was in nature of being detected by enemies; the sonar signal customarily used would alert any enemy to its location. If detection was so unfavorable, why would submarines not always run silent? The answer is obvious - the sonar signal gave the technician enough information to navigate the sub safely through waters at high speeds, whereas the lack of signal does not. It is the same with sonar using animals in nature. Without an active sonar, bats can't fly or feed, and wales would be stranded on the surface of the water for all time.


                We use the term FlashSonar, because the ideal sonar signal resembles a flash of sound, much like the flash of a camera, and the brain captures the reflection of the signal, much like the film of a camera.


                Perhaps the greatest advantage to FlashSonar is that an active signal can be produced very consistently so the brain can tune to this specific signal very intently.  This allows for relatively easy recognition of echoes even in complex or noisy environments.  It's like recognizing a familiar face or voice in a crowd. The more familiar is the voice, the easier it is to recognize. The characteristics of an active signal can also be deliberately controlled to fit situations. For example, consider the two main applications of sonar in nature - orienting and targeting. Sonar used for orientation usually takes the form of signals produced less frequently, and often at higher volumes. For targeting, sonar signals are emitted more rapidly and with decreasing volume as the target is scanned and approached. The brain is primed to attend to each echo by virtue of its control over the signal. Since it knows when it is about to produce a signal, the brain arouses to attend specifically to the results of that signal. It is unlikely that arousal to attention of this magnitude can be continually maintained.


                B. Social appropriateness of clicking:


                Some have raised concerns that clicking may be considered socially inappropriate. Our focus is on the discrete use of a click, which the user adjusts according to environmental situations. It is not generated louder or more frequently than is needed, nor is it made with facial ticks. Although it is possible to use sonar signals that are distracting, we have encountered very rare instances of the general public expressing any concern about the use of a tongue click for sonar with oup method. We have observed and our students report that the sighted public consistently does not seem to notice or care. This is true among children and adults. What is noted is that active sonar users tend to carry themselves with erect posture, they tend to interact with their environment gracefully, and they tend to look engaged. Other blind people, of course, do notice the clicking. Because of emphasized auditory attention among blind people, we find that blind people may assume that sighted people may be giving the clicks more attention than is actually the case. What sighted people do notice, and what causes heads to turn more immediately than anything else, is the long white cane.


                If arguments against the use of anything unusual had always been applied, spectacles, critical to the visual functioning of so many people in today's world, might never have been used for fear of looking strange. One could apply the same argument to using a cane, or a wheelchair, or any critical adaptive device or technique that stands out as unusual, but also changes the lives of those who use them for the better. Our perspective is that form should follow function, not the other way around. Which is more awkward: a blind person who can't find her way efficiently, gracefully and safely from one point to another, or one who gains the information needed to do so by clicking? To deprive a blind child of information that can be gained by clicking is tantamount to forcing a sighted child to go through life with eyes half-closed.


                C. The active sonar call is the basis of the FlashSonar approach.


                Until technology allows us to produce a more ideal signal, we recommend certain types of tongue clicks as the ideal signal. These are intended to be unobtrusive, hands free, and completely under user control without need for reliance on external elements or circumstances.


                D. Optimization of the call:


                In order for sonar to be optimized, four characteristics must be present - adaptibility of the signal by the user to given situations and environments, good alignment between signal and ears, minimal masking of the echo by noise, and familiarity of the signal to the observer. Only an active, self generated or specially designed signal ensures that these four criteria are met. Moreover, as discussed earlier, signals must be under the full control of the user, much as is our speech, in order to query the environment with maximum flexibility and optimal information gain. Cane taps and footsteps may elicit some information, but their characteristics will change depending on the travel surface, their directionality cannot be controlled, and such signals may not possess ideal spectral characteristics to maximize the echo and minimize its susceptibility to masking.


                An active signal that is self generated and whose characteristics are strictly under user control presents the advantage of allowing the brain to develop a familiarity with the signal. It is always easier to register something that we recognize. With familiarity, the brain can tune to the signal, and can therefore register it with less effort under broader conditions. It locks in most readily on signals that it recognizes. Also, since the signal is under the strict control of the user, the brain is always most sensitive to its effect. Bats always use active signals, and submarine technicians greatly prefer them.


                E. Types of Tongue Clicks:


                Research has found that, of all the signals producible by the human oral mechanism, tongue clicks hold the most immunity to noise, being most clearly distinguishable in the presence of noise. Phoneticists have classified and analyzed five distinct types of tongue clicks. Their names are not important. What we want is a sharp, solid snap, click, or popping sound that the user can control to soft or loud volume. This is usually produced by pressing the blade of the tongue (flat, middle part) firmly against the roof of the mouth, then pulling sharply downward to break the vacuum. The tip of the tongue should stay more or less stationary and NOT flop down to the bottom of the mouth to form a second "pop." When the tongue does this, we call this the "cluck click." A tongue click should produce a single, sharp signal, not a double click or clucking sound. Failing the sound being produced by the blade, a respectable sound may be produced by the sides of the tongue against the mollers. This produces the "giddy up" click. Another click suitable for temporary purposes is the "tsk tsk" click, the kind we often make to express disapproval. This is produced by the tip of the tongue against the top teeth. Whatever the click, it should ideally not cause odd facial expression, or be used too often or too loudly without cause. Soft clicks should generally be used to detect targets that are close or in quiet environments.


                F. Students who use echoes are often unaware that they are doing so.


                Moreover, they can be unconscious of trying to elicit echoes by such behaviors as tongue clicking, hand clapping, finger snapping, foot scraping, cane banging, or yelling. What they are really trying to do should be called to their attention. If their endeavors are obtrusive, they should be redirected to more discrete and more useful behaviors.


                G. Handheld clickers


                These may be used in certain circumstances. These can be purchased as animal training tools from some pet stores. The clicker should be cupped in the hand, button facing outward and forward, and activated by the thumb. Clickers should be sounded either at waist level or above the head, never near the ears. At least 1 second should span between press and release of the button. Clickers should never be activated rapidly, and should only be used out of doors or in open environments. They tend to have one volume only, and this is loud, too loud for indoor use or for use in detecting close obstacles. It's lack of flexibility makes it better for orientation rather than targeting purposes.


                H. Signals for very beginning exercises. In the very beginning some students may benefit from making a continuous "shshshsh" sound, or just using their voice. Some students may not have the breath support to make long "shshshsh" sounds. If this is the case, the transistor radio tuned off station (see VI-F) may help. This should be held just below the student's chin.




(For all target stimuli, transparency is ideal but not required.)


                A. Two, 1 gallon wide mouthed jars, and one jar about half the size of the others. It doesn't matter what the jars are made of, but they should be made of the same material. Plastic will be easier to handle for the exercises, but not required.


                B. Two large bowls or pots, at least 4 quarts. These can be salad bowls, mixing bowls, or whatever. Plastic is easiest to handle but not required.


                C. Three bottles of about a pint or quart - one medium mouthed and two normal mouthed of the same size as each other. Health juices and sports drinks often come in these sized bottles, with mouths slightly wider than is typical. Simple water bottles may serve for the normal mouthed.


                D. Five flat, solid, more or less square panels in the following approximate sizes: 20 inches on each side, 16 inches on a side, 12 inches, 8, and 4 inches on each side. (If circles are used instead of square, add about an inch diameter to each specification above.) Precision is not required, here. All panels should be made of the same material, but the material doesn't matter as long as the panels are hard and solid. Cardboard works. This may be obtained from a throw away box from a furniture or appliance store, or bike shop.


                E. One 20 by 40 inch piece of cardboard, folded in half to a 20 by 20 inch square.


                F. One small, portable AM/FM transistor radio. The radio is to be tuned off station on the FM dial, so you just hear static or white noise.


                G. A handheld clicker. These can be found at toy stores (in the shape of bugs or small animals) or pet stores (used for animal training).


                H. About 40 cubic inches of soft foam - enough to fill a 1 gallon jar or large bowl. This is not stirafoam, but soft, sponge like foam like that called "egg crate" foam laid over a mattress for sleeping comfort. Egg crate foam cut into fist sized pieces may be used, or soft packing foam purchased from a shipping or mailing supply store.




                A. Neural Activation of External Mapping:  Present throughout all these strategies, exercises, and activities is a view toward encouraging the student to interact with accuracy and precision with the external environment. This means directed reaching for stimuli, and moving toward, among, and around stimuli with precision. We discourage groping or fishing for what may be there, but rather a direct reaching for what is perceived to be there. This isn't to say that we discourage discovery exploration. Exploration is encouraged, but when we have opportunity to know what is there before reaching, we encourage active, directed reaching and precision movement.


                We believe that this activates the externalized mapping process. How this is best done is a matter for speculation, and will remain so until we understand the neural mechanisms better, and can cross reference neural development with behavioral development. In the mean time, we may use what we know and what we have observed and experienced to draw some inferences and make some educated guesses about how to activate the perceptual imaging system. Among other things, we take our cue from infants, which are perhaps our predominant teachers. Infants have to teach themselves how to externalize and  interact with their environment. Adults are both helpful and disruptive to this process. It's really up to the infants ultimately to figure it all out, and they generally do an okay job despite the well intentioned meddling. Sighted infants engage in two critical developmental milestone behaviors that we believe strongly activates this external spatial mapping process at an early age.

They engage in directed reaching, and they recognize faces.


                Whether or not blind kids generally engage in directed reaching and under what circumstances is a subject of debate. Suffice it to say that some blind kids do engage in reaching, but the degree of directedness  even among those who do actively reach is highly variable. It is more common for blind kids to engage in what we call discovery reaching, wherein the hands, arms, and whole body become tools for canvassing ones surroundings, just as a sighted child's eyes do. We believe this constitutes valid support to the child's development. At the same time, many blind kids tend not to engage in directed reaching with precision toward desired items of chosen interest. Patterns of passive reception are often engendered by items consistently placed directly into the child's hands without the child being stimulated to reach for a given item. Or, a child's hands are often physically directed to objects by others, or the child is expected to just fish haphazardly for objects. We hypothesize that these common scenarios can disrupt the development of a process by which the child establishes a dynamic relationship with the environment by mapping its elements relative to himself, and directing his interaction with these elements with precision. It is through the self directed interactive relationship that both the externalized mapping and executive function (managing one's affairs through personal choice) occurs. As this directed reaching phase is often missed with blind children, and is not necessarily reestablished nonvisually as they grow older, we infuse our program with continuous opportunities to engage in directed reaching for items and stimuli, as well as precision interaction with said stimuli. As students are called upon to interact with the world - negotiating, retrieving, approaching, or circumventing, we look for increasing levels of precision movement with grace, speed, and confidence.


                Blind infants recognize voices that are significant to them, and we can argue that this may serve the same social needs for emotional exchange. However, the acoustic recognition of voices may not serve the same needs for developing capacities for discrimination and classification of spatial elements beyond arm's reach. While faces may not be recognizable by their acoustics, surface features such as gross texture, absorption/reflectivity, and density (solid or sparse) can be perceived through sufficiently active and strategically applied sonar. We hypothesize that, for both perception of surface characteristics and directed reaching/precision, the clearer the image, the more boldly these details register within the neural network. This is where the quality of the sonar signal comes in, as well as systematic, discovery based exposure to exercises, activities, stimuli, and environments that facilitate the external mapping process.



                B. Observation:


                It is important to know what passive or active sonar skills the student is already using. Take plenty of time to observe the student's existing sonar skills. This can be done during other lessons. For example, instead of requiring him to trail along a hallway, allow or encourage him to walk down the hallway in his own way. See if he is able to direct his course between the two walls. See if he seems to be able to perceive when a wall or door is in front of him. Observe if the student stops independently or hesitates before contacting objects in the environment. How directed are his movements? If the student is able to do these things, he may be demonstrating some basic sonar skills. Some children demonstrate good skills at an early age with no instruction, but good instruction always helps improve skills.


                C. Tips for Teaching Tongue clicks:


                                1. Most students can make a suitable click without much training. Students can often learn by modeling. If students hear it enough, they eventually come to do it. For kids, we teach parents and siblings how to make the sound if the student can't do it. Usually, they can.


                                2. It may help to use a popcycle stick, tongue depressor, or spoon to show the students where to place their tongue. Tongue depressors come sterilized and individually wrapped. They are available from medical supply stores; some pharmacists may carry them. A doctor's office may provide a few as samples. Spoons are easy to obtain. Enlisting the help of a speech and language therapist may also help, if one is available. (They may also have some tongue depressors.)


                                3. A click that we try to avoid is what we call the "cluck click." This is a double click in which the tip of the tongue slaps against the bottom of the mouth. We want a sharp, single click similar to a finger snap or the pop of chewing gum.


                                4. For students who struggle to make a click, we teach tongue awareness. We identify two parts of the tongue - the tip (the forward part used to make sounds like "t," "d," and "l", and the blade of the tongue, used to make sounds like "k", "g," and "ng" combination. Have the student make these sounds. Have the student try to make a click sound while the student very gently presses a spoon or something beneath the tip of the tongue, just to provide some feedback to remind the tongue not to drop. Sometimes, this alone helps the student make a useful click.


                                5. If not, we inform the student that the click we may be looking for is formed with the same part of the tongue and mouth used to make the "k," "g," and "ng" sounds. Have the student gently hold the tip of the tongue still with the spoon while making these other sounds. Have the student try to alternate between making these other sounds, and a tongue click. Typically, a student can do this. It may help the student to imagine that a blob of peanut butter is stuck on the roof of their mouth, and he must use the blade of his tongue to pull the peanut butter away. The center of the tongue should be pressed to the roof of the mouth to create pressure, then pulled away quickly and forcefully, producing a distinct click. If a click is juicey or "sloppy" to begin with, it will usually tighten up or sharpen with a little time and practice.


                                One exercise that may be useful is the "king-kong" exercise. While holding the tip of the tongue against the lower palate just behind the top teeth, the student says "king-kong". Of course, they will sound very silly doing this with the tongue tip pressed tightly and not moving, and this injects a bit of levity into the experience. After a few "king-kongs", have the student lead directly from the "king-kong" into an alveolar click. After a few times, many students find this easy.


                                6. If the student just can't make any suitable click at first, have them produce a "ch ch" sound.


                                7. Children under the age of 6 or 7 will not generally respond to specific tongue click instruction.  Often, it will just put them off the process.  In this case the click can be modeled for him by others. Just do the click yourselves around him until he catches on.  Children typically learn by mimickery, and blind children are often particularly sensitive to this.  Otherwise, ask a speech therapist for help if it is needed.


                D. Systematic Stimulus Differentiation:


                We believe the brain learns to see by using systematic stimulus differentiation. This natural process may be sped up with formal instruction. The process of helping someone to learn FlashSonar, or any other perceptual skill for that matter, involves helping the student to move through a process of unconsciousness to consciousness to second nature. We conduct many of our activities unconsciously with a lack of awareness of how we do what we do. Often, we are also unaware of how our performance falls  short of where it could be. We start by making the unconscious conscious. Perception becomes deliberate and conscious. Once the process is made conscious, the  student can deliberately and with awareness targets skill areas needing refinement, and set  about refining them through this process of self monitoring. Once this is done, the skills being applied become second nature, but this is not the same as unconscious. They are second nature, because they are so easy as to require little attention to execute. We are still very much connected to what we are doing, we just don't need to concern ourselves with maintaining vigilance to that process. Lack of consciousness or awareness, on the otherhand, means a lack of connection to what we are doing, and how. Without this connection, we cannot intentionally manipulate and effect or own experiences and interactions. With very young children, we can move from unconsciousness to second nature, without necessarily passing  through the conscious phase. Or, if we do pass through that phase, it may be brief.


                This whole procession starts by tickling the brain into registering and processing subtle stimuli that may be beyond the conscious experience of the student. These stimuli often flow through our perception without conscious awareness, and the neural system may not have developed the full capacity to register or react to these stimuli. As instructors, we must help the student to "hook in" to these stimuli so that channels of processing these stimuli can be opened and made alive. The opening of these channels is often accompanied by a spontaneous sense or expression of excitement or sudden realization - the "ahha!" experience. This involves helping students to register and process stronger or more intense stimuli so that the brain may then open to processing subtler and finer stimuli. Perception of and reaction to the stimuli is key. For this to happen, the instructor helps the student to develop a relationship with the stimuli on their own terms. This relationship is not governed or even guided by the instructor. It is supported into development through aself directed discovery process, which is articulated eleswhere. Six strategies may help to do this - stimulus sensitization, stimulus clarification, stimulus comparison, stimulus association, stimulus shift, and refocusing. we'll give a general discussion of each strategy, and then more specifics as they apply to the specific activities. Some of these activities are very rudimentary, and may not be applicable or relevant to most students. However, some students, especially newly blinded ones or perhaps ones with hearing impairment or processing disorders, do benefit from exposure to these rudimentary steps.


                E. Stimulus Sensitization:


                As this term implies, we are helping students to "sensitize" to subtle stimuli, helping students to "hook in" to the experience. We start with sensitizing students to echoes, usually by having them detect and locate targets that are easy, such as large plastic panels or bowls. This helps them get a sense of what echoes sound like. Once this is established, we move to subtler and more complex stimuli. We find the level of stimuli into which they can "hook", then gradually move to subtler stimuli. Many students will pass through the earlier, more obvious stimuli very quickly, while others will need more time.


                                1. Noticing Strong Echoes. When the student is moving around the house or other environments, help her to notice the presence of strong echoes. For example, many children who are blind love to play sound games in highly reverberate environments such as rest rooms, breeze ways, or stair wells. Encourage the child to sing, repeat words after you, or clap in the bathroom or garage or other large, uncarpeted places without a lot of furniture or other objects that absorb sound. If the child makes noise in places with strong echoes, she can notice that her voice sounds different in these places than in other places. You can also make a noise in the bathroom and then move quickly out into the hallway where there is less echo, and make the same noise there so that the child can compare. Corners in a room also usually emit stronger echoes than other areas of the room.


                                2. The bottles are intended to give clear examples of hearing differences in the environment. They're used to prove a point. One can make the point that the sounds made by musical instruments, even though they may sound hugely varied to us, are actually the result of very minor changes in the instrument itself. A very small shift of one's finger on a guitar or position of a bow on a violin, or change of fingering on a flute produces a huge change in the experience of the ear.


                                                a. The student should be able to tell by ear when a liquid is reaching the top of the mid mouthed bottle or glass without touching. Liquids may be poured at different speeds to ensure the student is listening, and not just timing.


                                                b. Put slightly different amounts of water in each of the two standard mouthed bottles. The student should be able to hear the difference when blowing across the bottles, even if it is very slight. Only an extra tablespoon of water in one of the bottles will make it sound noticeably different. Students should be able to tell which one is the higher or lower pitch. If the student can't, increase the difference a little more at first. Again, the point is simply to begin heightening auditory sensitivity to changes that are more obvious before moving on to those which are more subtle.


                                3. The phase effect.


                                                a. Using the radio at low volume or a "shshsh" sound, or continuous vocal tone "aaaaaaah", move the large, solid panel from above or behind the student's head, to directly in front of their face. The panel should seem to appear suddenly before them. Don't move the panel too quickly, as the sound of your arm or the wind burst from the panel may arouse the student's attention. Be sure they can tell the difference between the panel being there vs. not there. If they can't, then clarify the stimulus by moving to the salad bowl (see Vii-E), or the jar. Once the student can hear the presence, then do the same thing with the large, flat panel further away.


                                                b. Next, try slowly waving the panel toward and away from the student's face. Discuss the change in phase as the panel moves. Can the student tell when the panel moves? Can they tell when it is just about to touch them? If not, try with the bowl, then move back to the panel. (This is an example of stimulus clarification.)


                                                c. Finally, move the panel from in front to the left, and from in front to the right. Have student say which way it moved. Keep the flat surface of the panel facing the student's head. In other words, don't just move the panel laterally along a plain from left to right, but move it along a circumference circumscribing the student's head such that the surface is always pointing at the student. Have the student practice scanning to hear when their "shshsh" sounds different. Or, by this time, the student may already be using a tongue click. This is encouraged.


                                                d. Note: While clarifying the stimulus using the salad bowl (see Vii-E) can be helpful, we don't always start out these particular sensitization exercises with the salad bowl, because the concaved surface, while more intense, can blur the clear phase shift affect that we want students to tune into. It's better if they can get it without resorting to the bowl, but not a crime if they need the bowl.


                                4. Stimulus Target Presentation. These include the jars and various panels (see VI). These are always presented to students with the instructor standing behind the student so that the instructor's presence does not interfere with the detection of the stimulus targets. These exercises should ideally be done in a large, open, nonreverberant, fairly quiet space (not absolutely quiet; about the noise level of a quiet day in a suburban residential neighborhood). If there are constant noises in the area, such as air conditioning or traffic, it's ideal if the noise is more or less evenly diffused throughout the environment so that it lacks directionality. If the noise is directional, then it should be placed behind the student so that sound shadows do not interfere with cuing of reflected sounds. If the exercises are performed in a large room, be sure the student is not facing a wall or corner that is too close to them. The stimuli are presented around the head as quietly as possible. It is best for the instructor not to wear long sleeves, because clothing rustles. When presenting a stimulus to one side of the head, the instructor should move both arms, including the empty one, but keep the elbow of the empty arm bent so that that arm is kept out of the student's auditory view. Moving both arms will keep the student from just cuing off the arm that moves, since they both are moving. But by bending one arm, the student won't be distracted or confused by the presence of the empty arm.


                                In general, these basic stimulus sensitization exercises move from presenting the jars first, then the bowl, then the flat panels. We generally move from the large flat panels to the smaller ones over time. We start at very near distances before moving to arm's length. Even if students seem well ahead of the game in their sonar, it isn't a bad idea to just zip through all the easy exercises anyway. It can give material to refer back to when the exercises get more complex. We always start with teaching the student simply to detect the presence or absence of stimuli, before moving on to location (left, right, high, or low). The various stimuli can be brought up later to represent real features of the environment - chambers of various sizes, alcoves, corners, and walls. The students will often be slow and methodical at first in giving their answers, but we want them to reach the point when they can instantly and almost casually give the correct answer without hesitation or second guessing.


                                                a. Sample Exercises:


                                                                (1) Present single large jar at various locations, and test detection. Discuss the sound. Start close, then move further back. Then, discuss the difference in sound between the large and small jar. First, present them individually, then present both at the same time, one to each side, having the student turn his head side to side to click or make some suitable noise into each. Discuss the difference between the size. Next, fill one of the large jars with foam, and repeat the stimulus differentiation exercise, discussing the difference.


                                                                (2) Compare the "bowl" sound to the "jar" sound. The jar may sound more hollow than the bowl, more like a chamber. Also, present the large bowls to each ear simultaneously but at different distances. Have student state which is further, which is closer. Start with very different distances, then reduce the difference.


                                                                (3) Repeat above exercise template using the flat panels, but don't compare size; compare panel to bowl, bowl to jar, panel to bowl or jar, etc. It may help to present both stimuli together to right and left, rather than alternating. Student can say, "the bowl is on the right; the panel is on the left." Or, "there's a panel above me and also one to the right." Discuss the differences in sound. Again, the bowl should sound more hollow than the flat panels. Also, the panel exercises should be done interspersed among other exercises (see below), not in an unbroken series. Encourage students to scan with their heads to differentiate the presence from absence of the panel from one side to the other. When doing distance differentiation, never use different sized panels, but always the same size.


                                                                (4) After doing a few of the exercises above, present the long piece of cardboard folded at 90 degrees as a corner, but don't tell the student what it is. Discuss what it sounds like, and what environmental feature it may represent.


                                                                (5) The exercises above can and should be repeated using real environmental features, such as blank walls, fences, and rooms of various sizes. Students can place their back, front, and each shoulder to a wall or fence after being disoriented. Start at a distance of about a meter, then increase to perhaps 20 meters. Note that some students may find sonar characteristics easier to hear at first from greater rather than lesser distances. Real environment exercises needn't be put off until all panel exercises are complete. They can be conducted between and among the panel exercises for the sake of variety and stimulation. It is often useful to the student to start to see the application of these exercises early in the program as this may not be self apparent, especially for young ones. In fact, young ones may not stand long for these silly drill exercises; they will probably need a more experiential approach involving real features most of the time. In general young ones do learn better when movement is involved.


                                                b. Special Considerations:


                                                                (1) If students can't do a tongue click (see V and VII-C), have them use a "ch ch" sound instead.


                                                                (2) If students have difficulty detecting these targets using a pulsed signal, try using "shshsh" or the radio at low volume placed at chin level. It may help to move the panel toward and away from the face with the continuous signal, and discuss the sound of the change. Can the student tell when the panel or bowl moves? Can they hear it move from side to side, and which side?


                                                                (3) If students don't seem to be able to hear the objects, try detection of large walls at distances of 15 or 20 feet. Discuss what the sound is like, a distinct echo, as we turn in different directions. Discuss how the sound changes as we get closer or further away. A pulsed signal gets closer or further from its echo. As we get real close the echo merges with the signal. Once the student understands the sound of presence, go back to the panels.


                F. Stimulus Clarification:


                When students are unable to register or describe a stimulus consistently, it may be that the stimulus needs to be clarified. There are generally three ways to do this.


                                1. Representation. a similar but more detectable stimulus may be used. For example, if a student cannot detect an opening in a wall, say an open door, find a room that is highly reverberant (larger or less furnished) that the student can hear more clearly as he or she passes the opening. Another example might be if a student has difficulty locating interior corners, he will likely be better able to find a large alcove. One can discuss the sound of an alcove, and relate it to the similar but less "hollow" sound of a corner. Alcoves and corners tend to be easy to detect and locate, because they throw back most of the acoustic energy to the sonar user.


                                2. Intensificationccbdda Bring the student closer to the stimulus, or use a larger version of the stimulus, such as increasing the size of the open door or branching corridor. This serves to intensify the stimulus under investigation.


                                3. Elumination: use a different sonar signal for that exercise. If the student can't detect the stimulus with a pulsed signal, such as a click, perhaps she can with the radio or clicker. This strategy sheds a different "light" on the stimulus that may cause it to stand out so the student can detect it more easily. Then, go back to using a tongue click.


                G. Stimulus Comparison:


                It may help to compare directly one stimulus with another. This is particularly useful when instructing registration of feature characteristics - dimension (height, breadth), location, and density (see IV). It may help the student to register these signature types when they have a basis for immediate comparison. For example, if a student is having difficulty registering foliage, confusing it with various types of fencing, it may help to find a location where both types of stimuli are immediately available. One can find locations to compare trees to poles, retaining walls to hedges, a car to a truck, a building with an awning to one without, a wall to steps, a wroughtiron fence to chainlink, etc.


                H. Stimulus Association:


                Stimulus association is the conceptual version of stimulus comparison. Instead of comparing elements in the environment, we are comparing them in our minds by drawing upon mental references. For example, when facing a hedge, a student might say, "It sounds solid?" We might reply, "as solid as the wall to your house?" "No, not that solid," she might reply. "As sparse as the fence of your yard?" "No, more solid than that," she might answer. Now we have a range of relativity to work with. "Does it remind you of anything else near your house, maybe in the side yard?" "Bushes?" she might query. "But what seems different from those bushes?" "These are sort of flat like a fence." If she can't put the word to it, we have her touch to determine that it's a hedge, and we may discuss why it sounds the way it does. This strategy is often used in discussing and describing stimuli. As students build up more of a repertoire of experience and understanding of acoustic imaging concepts, they can draw on this experiential base to understand and work out new stimuli. For example, when a student is having difficulty identifying or describing a feature, such as a palm tree (because of its seemingly solid, flat branches), one might ask "what does it remind you of? What are its characteristics?" We might discuss other trees we've encountered, and talk about how this one seems similar and different. When we are learning to find entrances to buildings, we often discuss what alcoves sound like. When finding open doors, we may discuss what branching corridors sound like. When learning to cross a street toward a building on the opposite corner, we may talk about what it was like to cross the open field or parking lot to a building on the other side. We often refer to beginning exercises when coming to understand the more advanced ones.


                I. Stimulus Shift:


                The stimulus shift paradigm is used by psycho-physicists to teach a student (subject) to register and respond to one stimulus by substituting another, more powerful stimulus, then fading that stimulus gradually so that perception of the subtler stimulus builds. For example, a student may have difficulty finding and approaching a tree trunk. The canopy of the branches can obscure the trunk. It may help to place the radio at the trunk, and have the student approach that at first. The student gains experience orienting toward and approaching a sound source. At first, the student is reliant on the sound source. But, the sound source is reduced gradually in volume. Without realizing it, as if by magic, the nervous system gradually keys into the echo stimulus as if the radio were still on. It's a kind of neurological bate and switch - a way of tricking the brain into thinking it's responding to one stimulus, when it has really learned to adapt to and register and respond to another.


                J. Attention Stabilization:


                Due to frequent emphasis on passive guidance by others, many students may not be accustomed to placing their motor system under the guidance of their auditory system. Also, congenitally blind children often tend to focus their attention into their heads, or on to matters of cognition other than the physical environment, such as the social environment. They often focus on what we call "in the head" environment, or focus on social engagement with a high degree of linguistic rather than spatial processing. There's nothing wrong with these focuses, but we'd like to encourage a balance. Recent blindness, or long time lack of self directed movement will exacerbate these tendencies. The perceptual system often becomes disrupted by passive reliance on guidance on the part of supporters and professionals. The inter-connection between the motor and visual systems is well established, but the inter-connectedness between the motor and auditory systems, other than for balance through the vestibular system, is much less understood. It is often assumed among perception experts to be of no great affect, but there are notable disagreements on this point, and this controversy is beginning to fade with new data. Whatever the case, it is probably true that the auditory-motor connection is more tenuous than the visual-motor connection. For this reason, the auditory-motor connection often appears to benefit from an "assist" development. In trying to work out this connection, the perceptual system may become confused or overloaded at times for some students, requiring a moment of pause and refocus. This can be facilitated by an instructional agent. For example, when asked to locate an object or to move in a circle around one, students may begin to meander near or around the object, eventually wandering away from it without realizing it. They may do this even when they know where the object is. It often helps simply to bring the student's attention back by asking, "where

is that pole?" Or, it may help to instruct them to "stop, face it, now go for it." Students can do this surprisingly well. On one occasion, we were working with a sighted person under blindfold for a TV segment. He was learning to find a minivan in an empty parking lot up to 20 feet away from his starting position. He had had two or three successful finds, and we had increased the distance. As he was searching, we could tell by his body movements that, consciously or not, his perceptual system had registered and noted its location, though still tenuously. But, the presence of the camera man was pulling his attention off track, and he began to wander. He was told, "You know where it is. Don't let the camera man pull you're attention away from your objective. Re-establish your course. Trust in what you know." At that his wavering reduced, and he pendulumed his way back on track as if drawn by a distant magnet until he reached the van. He reported that helping him refocus at that crucial moment was essential. Helping the student stop and refocus before they get too far off track can actually help them to adopt good perceptual habits of presence of mind, attentiveness, maintenance of conscious awareness, and self-trust. Usually, this is best achieved by asking strategic questions or dropping thought provoking hints, rather than by giving directives, descriptions, or explanations.


                Some students' attention just seems to be everywhere but on the activity at hand or the environment around them. Many students develop a coping mechanism of accessing the environment through others, rather than by their own self direction. To an extent, this can be adaptive as long as it doesn't limit the student's opportunities for activity, or pose an undue burden to others. Again, we look for balance. Other students may just be stuck in perseverative language about anything and everything except what's happening now. Or, they may get stuck on a sound or texture, and be unable to move on in their attention. With some students, we may set down parameters of interaction. For example, we may explain to the student that we will engage the student's conversation when that conversation pertains to the immediate activity, or to the immediate environment. Conversation about anything else will not be engaged.


                Another approach often found helpful is placing a bean bag on each shoulder, or perhaps the top of the head. This often has an amazing affect on the student's ability to slow down and focus. Rather than pose a distraction, the process of keeping the bean bags from falling seems to heighten attention globally. It has been found useful in remediating certain reading and learning difficulties in sighted kids. It may do this by causeaing an automatic bio-feedback loop, which gently encourages attention. It can also keep those bouncey, jiggley kids from bouncing and jiggling too much. Placing the bean bags in spare plastic produce bags may increase the affect, because it's easier to hear the bag when it falls. For students who are reluctant to do this, We may make it a kind of game by wearing the bean bags ourselves, and seeing who can do it the longest. We let the students know that we are willing to engage in whatever task or activity we pose for them; that's only fair.




                A. Maintaining various facing relative to a flat surface (see exercise Vii-E-4-a-(5).


                B. Orienting to and moving toward an object:


                Position student about 8 feet from a wall and ask him to approach the wall directly. Increase the distance over time to 60 feet or more. Some students may need to be reminded to face the wall first before moving toward it. If student has difficulty with this, it may help to place a sound source (the radio) at the wall, and gradually reduce the volume of the radio so that the sonar sense will take over (see VII-I). It may also be easier for some students to localize and approach walls more distant first, then closer. For some students, the time delay aspect of sonar at distances is easier to hear than phase cancellation at close distances. Students should also learn to approach smaller objects, such as a pole, tree, or bush. It is common for children to meander around an object, even when they know where it is. It is as if they're nervous system hasn't attached movement to auditory perception, such that auditory perception can guide movement. The student may need to practice turning first, then moving toward the pole. Finding the trunk of a tree may also be done, but the presence of the canopy may reduce the figure ground of the trunk. Student should practice moving toward a wall from a distance, then gracefully turning before reaching the wall and walking parallel to the wall.


                C. Alcove and interior corner location:


                This is simply an activity to learn to find a corner. A corner is needed with at least 3 meters of clear space before it. This may include detection of alcoves, such as an entrance alcove. This can be done in an auditorium setting. The student is positioned so that he is facing oblique to the corner. The student practices turning and moving directly to the corner. Some students may need to be reminded to turn their body first to face the corner, then move toward it. Distance should increase to about 15 feet. One can have a student move from one corner of a room diagonally to the other, sensing the opening of the corner behind them as they move away, and the closing in of the corner in front of them as they move toward. The room can be 15 by 15 at first, but then larger rooms should be used. It can also help to place various obstacles in the way, between the corners. The student may not be expected to detect all the obstacles without touching them, but should be able to maintain orientation and direction from one corner to the next while navigating among the scatter of obstacles.


                                1. Students should first be able to turn toward and travel directly to a blank wall from 20 or 30 feet.


                                2. If student is having trouble, it may help to position student about 5 feet away from the corner such that she is exactly facing the corner. Have her feel it with her cane. Then, ask her to turn and face "the right wall", then "the left wall" just as if turning her head to the panel or wall. It may also help to have students find the alcove first before finding a corner. She may wish to practice finding the opening to a large alcove, and traveling into and out of it.


                D. Tracking Course Boundaries:


                This involves being able to guide one's motion auditorily along borders and boundaries, such as walls, fences, a row of poles, lines of foliage, hallways, or aisleways in stores and parking lots. Start with solid, continuous surfaces before moving to sparse or intermittent features. Also, start with shorter distances before increasing distance. Distance may be increased to about 30 feet; wide corridors may be found in transit stations, airports, and suburban alley ways. When boundaries consist of clusters of elements, such as tables and chairs in a restaurant, individual elements of the path boundary may not be discernable, but these often cluster or aggregate to become detectable as a unit. For example, when winding one's way through a food court or restaurant, one may easily be able to thread one's way pretty gracefully among the furniture with minimal contact, without necessarily being able to distinguish or recognize any given piece. Encourage students to move at a moderate or brisk pace, as this will make this exercise easier. If they have trouble, it may help to use the radio pointed at the wall. It may also help to use the stimulus shift paradigm (VII-H) - placing the radio at the end of a long stretch of wall at the same distance that the student is to walk from the wall, such that the student walks directly toward the radio. Lower the volume over time so that the sonar takes over. Have student turn an exterior corner and maintain parallel distance. Some students may find it easier to travel straight down a corridor before paralleling a single wall. Also, it may help some students to do the centering exercise.


                E. Centering:


                Here, students learn to center themselves between two surfaces. Find or arrange two more or less flat surfaces about 8 feet apart. The two surfaces should be approximately similar in nature. It is best if the two surfaces are in an otherwise open area. They could be tables stood on end, or parked cars, or trash bens, or a wide corridor, or easels holding large boards. (The surfaces don't necessarily need to be precisely flat, but they should be uniform to each other.) Situate student midway between the two surfaces, and explain that she is centered. Have her feel the equal distance with her cane. Then, disorient and re-situate with the student much closer to one side, and ask "which side are you closest to." (Young children often cannot answer this question when put this way, even when they know the answer. It often helps to ask "which side can you reach right out and touch?" Or, "go to the side you can touch the easiest or quickest.") Then, re-situate students so that they're near the center, but definitely not centered, and ask them to center themselves. They will often get close and say they are. It very often helps to then simply say, "You're close, but you're closer to one side than the other. Which one?" Nine time out of ten when asked this question, the students can state correctly which side they're closes to, and center themselves more closely. We don't expect exact centering right away. If they're within a few inches, we just tell them they're good. We don't push for "exact" centering until they've advanced considerably. Increase the distances between the two surfaces to about 50 feet apart. (For this, the surface should be large, like between two buildings.) If they really can't get it, then refresh using flat panels "which one's closer?" (see VII-D-4-a). It may also help to skip to the surfaces far apart first, then move to the closer ones.)


                F. Circling:


                The student should be able to walk in a circle around a large-ish object in either direction, and stop at the point of beginning. It doesn't need to be a circular object; it may be a minivan, large column, kiosk, a display case, a tree, or whatever. The object being traveled around should stand in otherwise pretty open space. Large objects should come first before smaller objects, such as poles or bushes. There should be some defining feature that indicates the starting point. It can be the presence of another object, such as a distant building, or it can be another noise, such as traffic sounds. A student might even be ask to use a compass or the sun, or the wind, or some unique characteristic in the ground. Otherwise, the space should be fairly open at first, but can be more congested later. Some beginning students may wander far and wide from the circle, not realizing they've lost it, because it fades gradually out of their perception. When a subtle stimulus fades gradually, one often doesn't realize it's fading until it's gone. Stabilizing attention often helps, here. We may ask, "Where's that (thing)?" Students can often reorient themselves quite well just by this question. They may need to stop, reorient, then continue.




                A. Moving among obstacles with goal direction:


                The traveler can learn to move among obstacles, maintaining goal directedness, with little or no physical contact with obstacles through body or cane. We generally start by approaching and avoiding a single, large, solid, stationary obstacle first, before advancing to smaller, sparser, possibly moving obstacles. We further advance to threading one's way among obstacles, while maintaining orientation. Obstacular environments may include department stores, furniture stores, parking lots, restaurants, classrooms, forests, or any cluttered space. Children may have the advantage here, because their reduced height makes everything around them perspectively larger and more detectable.


                B. Precision detection exercises


                These can help to develop this skill. For example, have a student pass through a doorway on repeated occasions while slowly closing the door (thus narrowing the gap) with each trial. The student needs to determine the breadth of the opening, and ease through it without touching the sides. Also, having a student locate, reach for, and touch a pole without fishing for it can foster precision movement.


                C. An advanced form of this skill


                This involves what we call agrogating one's surroundings. When threading one's way through dense patches of obstacles and maintaining one's goal directedness, one does not need to distinguish and identify every single obstacle in order to be able to go around it. One should learn to chunk or agrogate the obstacles in order to get better cues about alignment. This can improve tracking course boundaries, especially if the boundaries are comprised of disjointed features rather than a solid border. A group of 3 or 4 tables might become one line. A bush with a tree or bench might become another line. A sign with a planter box and a mail drop box might become a third line, and so on - or all can be followed as one long line. It is like mentally drawing a line connecting multiple points; one can't take a line very well with just one point. In this way, the student isn't overwhelmed or disoriented by each obstacle, or lost between or among obstacles.




All objects, features, and events in space are constructed of dimension (height, breadth), location (distance, laterality, elevation), and density (solid, sparse, absorption). (See IV.) We can use this language to help students describe what they are hearing. A pole, for instance, is tall, uniformly narrow, and solid. A bush is sparse, broader, and short. A tree is narrow and solid near the bottom, but becomes broad and sparse with increased elevation; its breadth and laterality increase. Stairs are solid and near toward the bottom, but get further away with elevation. Here is where stimulus association, clarification, and comparison can really help students to understand what they're hearing, and learn to register and describe subtler characteristics. The question, "what does this remind you of," (association) can often stimulate realization about an event being beheld. Sometimes densely pact foliage will register as solid, because of the strong reflection of acoustic energy, until it is directly compared with something solid.




A student can learn to describe and image multiple events and layers of the environment. An example might be a bush in front of a wall, or a tree behind a fence, with a wall building behind that. The student should be encouraged to describe what she can hear most clearly, clarify that image, then concentrate on other elements. It's all in awareness of depth and distance cues, combined with distinctions in density. Distinctions in density may be likened to color contrast perception. Density distinctions can serve to make some objects really stand out from others. "What is close to you? What seems further away? How are they different?" Then, given what the student describes of the entire scene, what is their overall impression? "What is the picture? What are we looking at?" In our experience, more recently blinded people may be better at the imaging, the overall picture, even if their actual perceptions are more dull than students blind early in life. We believe this is because they have a lot of visual experience of the way scenes are arranged in the world. A long blinded person may be able to describe a scene quite accurately in terms of its characteristics, but still not be able to identify the object or scene the way one who has "seen it  all" can. Of course, blind kids who were free and encouraged to explore their environment prolifically can usually identify scenes quite well.




Here, we put it all together. Ultimately, we want to foster students' ability to establish orientation and direct themselves through space. We move through the environment in a goal directed way, registering and processing all the elements.


                A. Street crossing:


                The student can learn to register elements part way or all the way across a street, and use this information as a kind of beacon to guide movement while crossing. It is like crossing to a wall, except that we are processing other stimuli (traffic) as well. The attention is NEVER taken away from the traffic; that must be the primary cue. But, sonar goal direction can be closely secondary. We start with quieter streets first, then move to noisy. Sonar and sound shadowing can also help to register quiet cars at rest, and warn against large quiet vehicles in motion. It isn't necessarily the complete answer to "what do we do with silent cars", but it can provide an additional layer of warning and protection.


                B. Crossing a parking lot:


                This is a combination of orienting toward an object (a far off building) and negotiating obstacles, both stationary and moving. Once we near the building, other features of the building can be determined to help us direct our course to the entrance. The entrance is often located in an alcove. Of course, there may also be other auditory cues suggestive of the entrance.


                C. Self Orientation:


                Students can learn to orient themselves to any new area. The exercise might go something like this:


                                1. Choose a large, complex space - a park, school or college campus, transit station, playground, or shopping center.


                                2. Establish a highly audible, distinctive point of reference, or point of departure. This is often a large alcove or corner where two buildings meet. It should be detectable from 50 feet away or so.


                                3. The students practice leaving the point of reference, and locating three to five distinct elements of the environment. They should be distinctive from each other. Student may touch them for varification, but should identify them, or at least describe them first. The student should then return to the point of reference, then go back to locate and identify each of the elements they had found. Students should not just keep to pathways, but should be encouraged or even required (as part of the exercise) to cut across open space. (That's where the most fun is.) Objects might include distinctive trees or poles, park benches, trashcans, pavilions, fences, retaining walls, other buildings of unique character, steps, bushes or hedges and other plants, distinctive arrangements of objects, a particular vehicle in a nearby lot, etc. The student should be encouraged to repeat the exercise with larger numbers of elements or different elements - not more than 10, but the elements should be further and further from the point of reference. Ultimately, the student will establish other key points of reference relative to each other, and objects or features of smaller detail relative to those. Students may use other aids to help, such as a compass. The student may also make occasional use of public assistance if they've lost their bearings in returning to the reference point. Engagement of public assistance is an acceptible means of wayfinding. However, for sonar exercises, we encourage use of sonar as the primary means of information gathering and self direction. So, we ask that engagement of public assistance be kept to a minimum at first, until we find the sonar sense developing. Obviously, if the student continues to struggle with this advanced despite all instructional efforts, mutual engagement of public assistance can become the primary means of wayfinding for some students. This could even be a great GPS exercise where students practice mapping their environment. In fact, a very advanced student may create a tactile map of what they find. This process can be applied to orient oneself confidently and enjoyably to any type of space.


XIII. Over the top exercises for over the top students


It may be that different people try different exercises. Not everyone will be good at or necessarily want to participate in every exercise.


                A. Refined feature discrimination and location:


                                1. Various, distinct objects are held by someone while the echolocater discerns the differences and key characteristics, with a view toward identification if possible. dis The echolocater then touches each object to align the auditory image with the tactual one. Then, the echolocater is presented again with the objects randomly, and must identify.


                                2. Similar to the last, but objects are hung from the ceiling of a large room. Echolocater must locate and describe each object, with a view toward identification if possible. Then, echolocater touches each one, and must then relocate each one as requested by the instructor.


                B. Target practice:


                Targets of various sizes and concavities are erected, and echolocater must challenge himself to hit various targets from various distances, either by throwing a ball or using a water gun. Ben Underwood really was able to shoot hoops without a sound source on the basket from about 10 or 15 feet with about 75% accuracy.


                C. Scene representation:


                Present the echolocater with a scene with which he is not familiar. He must draw or somehow represent the scene before him.


                D. Bicycling:


                We get our hands on some mountain style, cruiser, and/or BMX freestyle bikes, and some small to mid sized helmets. We will also need some zip ties or cable ties.


                                1. We find a large, open space with some widely space obstacles, and preferably some buildings. School grounds, high school parkinglot, or church parking lot can work. We practice riding around the area, detecting, circumnavigating, and avoiding the objects and features. Often, we start by riding back and forth along a building line before venturing out among the obstacles. Eventually, we arrange an array of human obstacles for the riders to rider through.


                                2. We tao the bike show into a residential neighborhood where people ride around at their leisure, remaining straight in the street, turning corners, U-turns, riding up to and stopping just before a curb, and turning into driveways.


                                3. If we can get our hands on some tandems, we practice same as above, but piloting a tandem.


                                4. For folks who do not or cannot apply FlashSonar to bike riding in our time frame, and who still want to try their hand at solo riding, we place a zip tie on the rear fork of someone's bicycle so that it creates a sound beacon. Then, the individual can follow, we still controlling his own bike.




Some of these exercises, particularly the last few, can be quite conducive to student groups. Students can help each other to register object characteristics and identify objects, image scenes and discuss what is perceived, and actively find their way around new spaces. The group energy often helps and encourages students to reach heights they might not otherwise reach. The group dynamic can serve as a tremendously motivating process. It's very interesting and powerful to observe a group of students come to consensus about what they perceive, and how best to find their way.




                A. Cane Msers: For cane users, it is our experience that the program is most effective when conducted with the student using their cane. At first, we separated auditory and cane training, but have sense found that combining them has best results. It is true that the student may find the exercises easier without the cane, but we feel that for most students the pay off is usually greater and speedier if the cane is used from the beginning. It can be quite frustrating for both student and instructor to have students perform the exercises well without the cane, only to have their hard earned performance fall apart when the cane is re-introduced. Use of the cane facilitates self directed discovery and, for most students, there is much to be said about the stimulating affects of self directed discovery on perceptual development.


                B. Partial Vision: With regard to partial vision, we do not make a regular practice of blindfolding children. We believe that partial vision, as a component of the perceptual system, deserves and warrants attention, often very specific attention. Unlike many, we are strong believers in visual efficiency. We do not believe that "people do not need to be taught how to see."


                There are often situations when degrees or quality of partial vision simply require integration of nonvisual skills and perceptions in order to recover and enhance a quality of self directed achievement comparable to ones peers. What we call the "visual system" occupies about 403people of the brain, and seems to be the default system for spatial processing. What we call the "visual system". is really an imaging system, that can be recruited to construct dynamic, operational images from nonvisual inputs. This can happen naturally without specialized instruction or therapy, but for many reasons, it often does require assistance and support to do so. Anyway, even though the imaging system can and does integrate multisensory input for image construction, the nature of its neurology tends to favor visual input, and that is usually where the imaging system defaults. This may not be a problem for standard, day to day functioning for your typical, run in the mill sighted person, but it can be a real problem for one who's degree or quality of visual input isn't up to the task - isn't quite enough to make the wheels turn properly, so to speak, or to use another analogy, not quite enough data to allow the computer to process properly - whichever you prefer. Now, the imaging system may really need some help to construct these images, and this help will probably come from increasing support from nonvisual perception and skill.


                However, since the imaging system tends to default to visual input, it may be necessary, and we have often found it so, to isolate some or all of the nonvisual skills and perceptual training from visual input. We call it "isolate, then integrate." FlashSonar is one but only one very good example of when a perceptual process really needs to be isolated from visual input in order to give it any chance of developing. Students simply do not develop FlashSonar or many other skills when you have the visual system grabbing at visual information, often erroneously, thereby usurping, short circuiting, disrupting, or whatever, the development of other areas of integrated perception. It may and often does become prudent to to offer experiences of visual  occlusion during portions of the perceptual training. These spans of visual occlusion may provide opportunities for nonvisual perceptual capacities to take hold and grow, where they might otherwise not.



                Visual functioning generally interferes with sonar information as it tends to dominate perceptual attention (for better or worse). However, it is surprising how motivated many partially sighted students can be to learning FlashSonar. They often know just how dependent they are on the little vision they have, and how fragile that dependency is. When the lights go down, they go down hard on these students.


                FlashSonar seems to be particularly helpful to students who have visual field loss, as students can learn to use it to fill in these gaps. For these students, FlashSonar will often serve to allow the students to register objects or features outside their visual field. Then, they may bring their vision to bear on the target to gather more information. This method can reduce the need for constant visual scanning.


                For partially sighted students, we find that it seems more effective to isolate, and then give specific attention to integrating. During auditory image training, the visual system is literally adapting to process nonvisual information to extract spatial images. For this to happen, the visual system seems to need a period of disconnect from the eyes. It seems to be hard wired to receive and process information from the eyes by default, so it needs to be insulated from the eyes in order to foster new connections and operative pathways for nonvisual integration and image construction.


                Since partially sighted students are using their vision most of the time between lessons, they tend to learn auditory imaging more slowly. However, they sometimes have an advantage in that they may have visual images to draw upon in learning how to image nonvisually. In other words, the imaging system seems to be able to apply previous visual experience to developing a nonvisual imaging process.


                Students with light perception or visual memories often confuse sonar images with visual images. They seem to "see" what they hear. They may say: "I can still see the wall," even under a blindfold. The brain can interpret sonar sensation in a visual reference - causing crosstalk between the sensory channels. This is called cross modal processing, and may also be referred to as synesthetia. With the exception of very young children, it may be helpful to students when we explain to them the difference between what they see, and what they hear.


                The strategic use of blindfolds and isolating headphones or earplugs can be helpful here. Some with partial vision will strain their eyes. But when their use of echoes is brought to their attention and refined, they may find it less necessary to strain. This is especially beneficial to those with fragile eye conditions.


                Our practice under such circumstances is to offer occlusion about 75 3people of the time, more or less depending on lots of factors. The isolation phases allow nonvisual skills to take root, the integration phases allow opportunity for multi-sensory processing to develop into truly integrated perception. If the isolation phases are denied the student, the nonvisual capacities that may indeed be necessary to support self directed achievement may not take root and grow. Likewise, if the integration phases are denied the  student, then the integration process may not reach critical mass, as it were, and never quite come together.


                We have observed that some students who go through mandatory occlusion training at some of the emersion centers do struggle with visual integration, because the integration phase doesn't sometimes seem to be instructor supported. We know this from conversations we've had with NOMC'S as well as COMS'S and some students. Also, visual adaptation skills may be lacking, such as monocular use and visual scanning. That question has been raised to suggest that maybe this tradition emerged partly out of blind instructors leveling the playing field, although there is much more to it. As blind instructors ourselves, we find visual efficiency and integration training to be quite challenging, and we can see how many blind instructors would gravitate away from it, much as sighted instructors often gravitate away from the finer points of auditory training. This isn't by any stretch to implicate all blind or sighted instructors in either category; it may just be a tendency. We appreciate visual training, as we regard working with the perceptual system as a kind of giant puzzle.


                Now, speaking to occlusion - we do not force occlusion on students. If we force occlusion on kids, we lose all hope of developing rapport, and instructional efficacy goes out the window. If we try to force occlusion on adults - well, pretty much the same thing happens. What's the point of that? However,                so not fair or respectful to the student not to offer occlusion opportunities as a potentially invaluable benefit to perceptual development.


                In this connection, we have developed many ways to support students to at least give occlusion training a fair try. And no, this doesn't include threats or brute force - both of which we have witnessed. Many older kids like it, and younger kids generally adapt to it quickly.


                We tend to use sunglasses blocked off in various ways, because students often like them and will accept them, and because they are generally more comfortable than blindfolds. Blindfolds can feel quite stifling, and be a real drag in the heat and humidity. Although wrap-around sunglasses or fish-eye sunglasses may be used, we do not concern ourselves too much with a bit of extraneous light sifting occasionally in from the sides. We see little reason to turn the lights completely out for all students all the time, especially when the likelihood of any given student going totally blind is remote. Should this be a likely prognosis for a student, then we may encourage wrap-around sunglasses or even industrial safety goggles.


                                1. Diffused Occlusion. Perhaps this is our favorite approach. We take several pairs of sunglasses. The student chooses which one they like. Often, offering a choice just makes the whole experience more intriguing and palatable, and perou the student places some stock in fashion. We lean toward the ones with big lenses or the wrap around kind, but not exclusively so. We have blocked off the back with criss-crossed, thin strips of tape. The idea here is to allow light into the student, but to break up the image enough that it can't be useful. This may take a little trial and error, since many students with very low vision are quite good at processing visual fragments. What may be incomprehensible to a  fully sighted person looking through diffused occlusion may still make some sense someone accustomed to using very little vision. Also, we want to ensure that this type of occlusion doesn't back fire, in the sense of prompting the student to have to concentrate that much more on visual fragment processing. But, with a little time, we can get it right. As long as there is some light coming in, the student, even very young students, will often accept occlusion, and even consider it a game. Students with very low vision often hardly seem to notice that they now can't use their vision anymore, and may adapt very quickly to nonvisual development. Some will say that it's less confusing and more relaxing to operate this way. Over time, if we want, we may add a little piece of tape here and there, until eventually the glasses are completely blocked out, and the student hardly even notices or cares. Again, this is done often in combination with nonoccluded training for integration purposes.


                                2. A World of Color. We use sunglasses again, perhaps totally blocked off, but with colored tape to make the world a little more interesting. Eyes that can see often really don't like seeing nothing, and those of us who have never seen nonetheless hold a certain respect and sensitivity to this. We may call it "the world of pink", for kids who like pink. Or, maybe we have different glasses with different colors that the student may choose from for that day. We want solid colors; not patterns or anything busy.


                                3. Occlude the Instructor. Students will often accept occlusion if the instructor is also willing to wear occlusion. As a rule, we generally do not try to encourage students to do anything that we would not be willing to do, or at least try, ourselves. For example, if we use bean bags to help support better posture, we also carry the bean bags, or whatever it is. So, if the student feels better if we wear occlusion along with them, why not, at least to start with. Boys like to play pirates, and the blindfold becomes an eye patch, except we use two eye patches, or we patch the eye that sees better.


                                Many sighted instructors, particularly non-NOMC'S, may feel at a disadvantage here if they are unable or uncomfortable to function with their vision fully occluded. This is understandable. Perhaps you give yourself a cheat whole to look through if you feel this is ethical, or perhaps you negotiate with your student to allow you an easement.


                                4. Darkened Environments. Maybe we conduct some lessons in a dark room, like a gym, auditorium, or multipurpose room, but with all the lights turned off and windows shaded - or lessons at night in a dark area. Obviously, lesson options may be limited under such conditions, but there's still much that can be done.


                C. Recently Blinded Adults: Working with recently blind adults as opposed to those blind for a long time:  Although the basic principals are pretty much the same for all students, there may be some differences working with recently blind adults, as opposed to those blind for a long time. For adults, research has shown, and it is our experience, that neuralogical adaptation seems to take place, at least in part, over about 5 years. For children, this may occur in only a year or two. This adaptation is as if the nonvisual channels have warmed up. However, these channels may be sluggish for recently blind adults. The situation may be somewhat reversed for newly blind adults, vs. congenitally blind people. In the former, the imaging system may be in tact, craving and reaching for information, ready to assimilate it into a dynamic, operational image, as it was accustomed to doing with vision. Yet, the nonvisual channels through which to gather this information may not be forth-coming as yet. On the otherhand, congenitally blind people may have moderately active channels for conveying nonvisual information, more or less, but if the student is relatively dependent or restricted, the imaging systems may be under-developed. For recently blind people, the full complement of abilities should be learnable to a functional level of proficiency. But, this will likely take longer and require more diligence on the part of the student. Developing these nonvisual channels may need to be addressed with care so as not to discourage the student. However, within a few hours, many students report and express an "ahha!" moment in which the echoes flash at them. They often report this as visual, and sometimes become quite delighted at the experience. Here they are seeing something when they had resigned themselves to never seeing anything again. We often foster this development by addressing their strengths which usually lie in an in tact imaging system. We will provide two examples:


                First, during a workshop, we worked with a blind woman who had lost her vision only a few months before. She was still quite emotional about it, but she was very motivated and enthusiastic. It was a struggle to foster development of even the basic skills. She was one who didn't warm up to the panel exercises. For sensitization work, we had to clarify those stimuli by using actual walls and corners. One of the exercises involved having her walk along a library book shelf, and stop where the shelves were empty (which gave off a decidedly hollower sound. If memory serves (this was 7 years ago), this was her first "ahha!" moment. Her exclaiming "ahha!" is what gave this technical term its name. Though she made huge progress and expressed her appreciations most wholeheartedly, she did not reach the more advanced abilities. The audience of attendees asked two congenitally blind rehab counselors from among them if they wouldn't mind undergoing some training in the advanced skills, to which they graciously agreed. Here's where the imaging differences were demonstrated. When it came to auditory scene analysis, the congenitally blind adults were good at detecting and describing various stimuli, but couldn't articulate the scene. Whereas the recently blind woman, once she heard the others describe the stimuli, could do so. For instance, when looking at someone's front yard, the congenitally blind adults might say, "There's something broad, tall, and sparse immediately in front of me. Behind it, there seems to be something tall but not so broad, maybe broader near the top. It sounds more solid. Then, behind that and further away, there seems to be something large and very solid." But, they often couldn't hazard a guess as to what they were looking at from a "big picture" perspective. The recently blind woman would then chime in and say, "Wouldn't this maybe be a fence with a tree behind it, and maybe someone's house behind that?"


                On another occasion, we worked with a teenaged boy blind for one year. We began with him by having him show us around his neighborhood in which he'd grown up. He was instructed to call to mind everything around him as vividly as he could remember. "Take me on a tour, and describe everything as if you were seeing it." This process seemed to stimulate his receptivity to the opening of nonvisual channels, and we posit that this may be true for many. We are not afraid to get very visual with our recently blind clients, while at the same time applying the exercise activities to open nonvisual channels.


                D. Congenitally blind kids:  When working with congenitally blind kids, we do not spend much time specifically on body concepts, backwards chaining (tactile landmarking), or focusing on the minutia of things like doors, chairs, or whatever else we might assume the child doesn't know "because they can't see it." Our focus is on child directed (adult facilitated) discovery. Daniel writes: "My spatial movement skills as a boy were nearly impeccable, as were most of my gross and fine motor skills. I could find my way around anywhere, and take anything apart and put it back together. Yet, I probably would have scored low on things like body concept, had there been anyone to assess such a thing (God forbid). When I swung my arms hard enough as a 5 year old, my hands touched something behind me. I don't know how long it took me to figure out that my hands were just touching each other. Until the age of about 6, I was absolutely convinced that the deep end of the pool had no bottom at all, and would have screaming fits if they tried to make me go there. I didn't know my right from my left till I was 8, and only then because I'd broken my right ring finger and had it splinted for a month. I couldn't tie my shoes till I was 9. I believed that there was a hill at every stop light. (Ever notice the car seems to pitch forward when you put on the brakes?) Yet, my travel and orientation skills were top notch even at 3 years old. In time, I just figured out through natural consequence how the world worked. Sure, there were things explained to me from time to time, but there was little in the way of formal concept instruction. I mostly figured things out by my own self-directed discovery, which I was highly encouraged and supported to do."


                Not only do we not think that specialized body concept training is particularly important, we don't really think there's any way of assessing it properly, or determining what the results of such assessments actually mean. A big part of the problem here is that most assessments of blind people are designed according to educated guess work by sighted professionals with little or no input from the blindness perspective. The resulting guesswork and its implications are, therefore, questionable in our opinion.


                It seems to be assumed a priori that congenitally blind kids will have problems with body and other spatial concepts. We have not necessarily found this to be so when the blind child has plenty of opportunity to explore and discover through his own self direction. This is the basis of many of our lessons with blind kids, and of our work with their families. It is in no way based on the things they shouldn't be doing, but on the freedoms they should be enjoying.


                There are certain issues of a social nature that do tend to pertain to congenitally blind children which deserve discussion, together with some perception based, discovery strategies:


                                1. Directed Reaching.  For sighted infants, vision provides a feed forward sensory mechanism that allows the infant to anticipate what may be around it. Directed reaching occurs in response to visual input. It serves to allow the infant to investigate and better understand the visual stimuli. The visual stimuli also gives the infant a sense of what to expect when reaching occurs. Although what to expect needs to be learned, so quickly learned, and it is learned in part incidentally by watching others even before the infant actually succeeds in reaching. Vision, then, provides an anticipatory sense of what is to be reached, even before contact is made with the items being reached for.


                                With blind infants, vision is not present to serve as a feed forward sense allowing for anticipation and self direction. As discussed in VII-A, directed reaching or discovery reaching occurs quite variably among congenitally blind infants. Auditory stimuli and incidental, tactile encouragement can stimulate reaching for many blind infants, rather directed or discovery in nature. Both are useful in helping the infant develop his relationship with his world. Some blind infants can remain fiercely fearless and unwaveringly inquisitive.


                                However, for many other blind infants, auditory stimulation may not be enough to stimulate directed reaching. The lack of visual stimuli may cause many blind infants not to be motivated to reach for items in their surroundings. Also, a certain anxiety may be present about taking the initiative to reach into unknown space. Perhaps the infant just has an anxious personality. Or, perhaps he attempted to reach or move, only to be met with shocking or otherwise negative consequences, such as an unexpected head bump, or coming abruptly into contact with an unpleasant stimulus that was not anticipated due to lack of visual preview. In such cases, some blind infants may learn to remain immobile, lest their hand, foot, or any other part of their body become implicated into unpleasant and up-setting circumstances. In such cases, many blind infants may simply remain quite still, just listening intently to what is around them, or retreating into their own head.


                                Caregivers child a case tend to manipulate the infant's body to interact with the environment. In essence, we guide the infant's reaching and exploration in the hopes of engaging him in the world. However, this process can quickly degenerate into a dependency of the infant on others to govern its movements through space, and can serve to establish anxious feelings about self directed reaching and movement.


                                Early cane training provides blind infants with a sense of being able to probe the environment around him. It serves a similar purpose of feed forward anticipation as vision does for sighted infants.


                                To support directed reaching, it is helpful initially when bringing items to the infant, to lightly touch the item to the infant's hand. This is just to stimulate interest in the item. Once the infant realizes that the item is approaching him, stop short of the infant's so the will be encouraged to reach for it. Over time, one can  hold the item further away to encourage a full reach. With items such as a pacifier or drinking cup, one can tap on the item, causing it to make a sound that will come to characterize the item. Or, one can attach a bell to the item.


                                2. Walking and cruising.  Near all children cruise along furniture and other surfaces in the development of walking. Sighted infants hold on for support for as long as they need to, yet always striving to move away from support. Before long, they are walking unsupported. Blind infants cruise as a means of physical support, but this physical support may also come to serve to form the parameters that define their world. Thusly, they may come to depend on physical surface as a means of maintaining a sense of direction and purpose, and this becomes their comfort and their understanding of the world. In such cases, movement through space become linking to contact with physical surface, and the prospect of self guided movement apart from physical space may become unimaginable for many congenitally blind children.


                                One convention we definitely avoid is encouragement to trail, square off, or heavy reliance on tactile landmarking. As noted, the blind infant is already in danger of developing a strong dependency on physical surfaces for his mobility. To further encourage this process is to establish it into a fixed pattern of dependency  that becomes almost impossible to break. Instead, we encourage the infant to hard and respond to the echoes from large surfaces and features, such as walls, inside and outside corners, and openings. These are usually easy for the blind toddler to learn to hear, and doing so can quickly stimulate confidence of movement in free space.


                                3. Infant Scaffolding. Sighted infants are generally scaffolded, supported, nurtured, encouraged, and celebrated to move through their development into greater and greater competence and self efficacy. Their first reach, first step, first jump, first throw. As the infant's competence improves, scaffolding is withdrawn, or modified to encourage more and more self efficacy.


                                Blind infants are also scaffolded, but the ongoing nature of it often progresses differently. The blind infant may not be driven in the same way to extend and expand competence and self efficacy. For a blind infant, scaffolding may easily become enabling to the extent that the blind infant comes to depend more, not less, on the scaffolding process. Their capacity to engage the environment becomes predicated on the facilitation of others. In this case, scaffolding is not withdrawn reciprocally to developing competence, so competence may not be driven to develop. The result is a cycle of learned helplessness in which the blind child becomes ever more dependent on others to govern his relationship with the world around him.


                                This dependency process may be exacerbated in the case of medical fragility common among congenitally blind infants. In this case, the infant really does require considerable care and nurturing, but the pattern of nurturing may become fixed, and not allow the infant to develop self efficacy. What started out as a genuine requirement of care lapses into a habit of enabling and dependency.


                                Here, the family may simply need some  gentle, understanding counseling to ease up on the amount of scaffolding being given. The philosophy and approach outlined here tends to show immediate impact. It isn't a situation of "if you do these things in just this way, someday, you'll get results." The approach is very relaxed and flexible, and the results are often immediate. This provides the family sound impetus and encouragement to take a more progressively developmental approach with the child.


                E. Working with very young children: We're not much of believers in instruction that is very structured. We take a perception/discovery approach, rather than a skills based approach. This tack seems to work particularly well with very young children. The youngest child we've taught cane training to was 18 months. The youngest child we've taught FlashSonar to was 2. However, We don't believe there's a minimum age. We might ask ourselves "how young can a child start to learn to see." The answer is that children start to learn to see from birth. Likewise, learning to "see" without sight can begin at birth with the right support. In general, we would say that experiential lessons in discovery are most effective with children. Engage children in what they like to do, which is usually play, and work sonar experiences into these. Also, we can't emphasize enough how critical and successful we have found working with the family. Family buy in can increase the student's success 10 fold. The following few examples may be helpful:


                                1. Find the box: Very young toddlers or infants often like to crawl into or under things. Find a large container, maybe a rubbermade storage container, or an open cardboard, and position the child near it. Entice the child by talking or making funny noises into it to get their attention. "See how boomy it sounds. Rrrrummmm." Then, see if you can get the child to find it themselves. The first time should be easy, because they heard you talk into it. But then, place the child at different distances and different angles, and encourage them to find it.


                                2.  Stimulate the child's interest in container play. Bring out several different containers, different sizes and materials. Play with him. Encourage him to drop different things into the containers to see what kinds of sounds they make. Drop the containers to hear what sounds they make.  Sing or make noises into the containers.  Such activities can serve to stimulate further interest in the auditory environment, just as visual games and bright colors can help stimulate visual development for sighted children.  The child may develop favorites among the containers.  Encourage him to give names to the containers. When he develops interest, hold a container near him, open side toward him, and encourage him to find it by making noises. In time, he will learn to find it by clicking.


                                3.  Auditory Space Recognition. Carry the child from room to room in his house, and encourage him to learn what room he's in based on its sound characteristics.  This is best done from the center of the room.  Have him name the room.  It doesn't necessarily matter what term he uses, as long as it's consistent.  But, it could be a good way to develop vocabulary.


                                4.  Stimulate interest in crawling into or under things - a table, into a cupboard, very large boxes, wherever.  You can make this into a sort of hide and seek game. Make noises with him.  See if he takes interest in the auditory environment in or under these things. You can do this same thing when you enter various environments that have different sound characteristics, such as the lift, an echoey hallway, or a large cathedral.




                                5. Hide and seek. For older children, we might set up a game of hide and seek. This works well for groups of blind kids. The rules are that one child counts to whatever while the others hide. They must hide near, under, or behind something that is at least as big as they are. This means that they have to find objects of  proper size. Then, the seeker must "look" for objects of a certain size, and check if anyone is there. If the seeker has trouble, she can ask for a hint. The hiders must clap their hands or click there tongues once, and the seeker needs to keep track of where she heard the signals coming from. You can set a limit on how many hints the seeker can ask for. We usually put the limit on three, but more may be appropriate. It may be helpful, especially with younger kids, to give  them a chance to exercise  their skills to explore the area first. This can be a good motivater to explore. We've found that kids generally very much enjoy this game.


                                It also works well for kids with partial vision, as it encourages visual scanning. We have played with a mix of sighted, partially sighted, and blind kids. In this case, it may be especially helpful to teach blind kids the concept of keeping the object they're hiding near between them and the seeker. As they hear the seeker approaching the object near which they're hiding, they should learn to quietly move around the object such that the object remains between them and the seeker, so that they remain hidden from the sight of the seeker. Of course, if the seeking is scanning effectively, he will more likely discover the hider, but the hider should, nonetheless, learn the strategy of maximizing his chances, as well as learn visual concepts.


                                6. Audified Ball play. You can audify a ball quite easily by placing it into a spare grocery bag, and tieing the handles together loosely around the ball. Then, we may bounce the ball against the wall, and intercept it as it comes back. If the student has to chase after the ball, he must maintain echo awareness to return to a point within tossing distance from the wall, and square himself so the wall is in front. Otherwise, the ball will just continue to bounce away eskew.


                                7. Explorer. Here, there is no real goal to the lesson, other than to explore. We find an area or large building that we think will be of interest to the child. Children often like large buildings with lots of corridors, stairways, elevators, and rooms of different types. We try our best to find everything interesting, and we try our best to keep track of where we are. We listen for differences in our surroundings, and keep track of whether things sound familiar or different. This exercise can also be performed in an intriguing outdoor area, such as a park. If this park has a playground or nice trees to climb, so much the better. In one park, there were large stone monuments, and a large fountain with steps that went up and around it - quite fascinating to explore, and wonderful to play hide and seek in.


                                8. Counting. Many students like to count things. By using FlashSonar, students can count poles, parked cars, trees, bushes, or open doorways. To do this, they need to be able to detect and discriminate what the objects are.


                                9. One student liked to ice skate. We practiced having him ice skate around the rink while keeping track of the outer railing, and listening for others around him. Another young student liked to ride his tricycle, so we found an area which had a very long wall, which had some twists and turns in it. He could ride his tricycle along the wall as much as he liked, and as fast as he liked. He could even venture away from the wall, as long as he could hear it well enough to return to it.




Although these exercises are meant for those working with students to stimulate your own sonar sense, you can do any of these with your students as beginning exercises.


                A. Procure a large and small wide mouth container. Glass jars are good; seashells are excellent. Speak into the open air, then into each container. Note how the containers sound different from the open air, and from each other. Close your eyes, and have someone hold the containers in front of you as you speak. Try to hear when the container is in front of you, and which one is the smallest or largest. Have someone else speak, and, with eyes closed, you guess which container is which.


                B. Hold the mouths of the containers to your ear. What do you hear from them? Do you recall the "ocean in the seashell" phenomenon? It is only sound reflecting inside the container. Can you hear the difference between small and large containers? Put each container at each ear simultaneously. Can you hear how each sounds different? With your eyes closed, have someone present the containers randomly to each ear. Can you tell when the container is present or absent? Can you tell which container is which, large vs. small?


                C. Position yourself about a foot from a blank wall. Take a deep breath, and, with closed eyes, pivot your body while slowly exhaling in a "shshsh" sound. What happens to the "shshsh" sound as you turn your face away from the wall? How about toward the wall? While pivoting, try to hear when you are facing directly toward the wall. If the "shshsh" doesn't work for you, try an "aaaaaah" sound.


                D. Position yourself about 4 feet from the wall. Take a deep breath, and, with closed eyes, approach the wall while slowly exhaling a "shshsh" or suitable sound. Now, step away from the wall while exhaling. See if you can bring yourself to within 6 inches of the wall without touching it. How about 3 inches?


                E. Stand in the middle of a sparsely furnished room with your eyes closed, and turn slowly while exhaling the "shshsh" or suitable sound. See if you can locate the a corner. Begin walking, and see if you can find the corner.


                F. In a car find a residential street with several vehicles parked along it. (A parking lot will not do for this exercise.) Open the window, and, as you drive, listen carefully to the sound of the car every time you pass a parked vehicle. The sound fluctuates. If you can get someone else to drive, try this with closed eyes, and listen through the passenger window. The effect is more pronounced here. You may even be able to tell by listening whether the street is heavily lined with parked cars, or sparsely so.


                G. In an area familiar to you, try walking with a blindfold and long-cane. Try perceiving things around you by echoes. Do not try to ascertain exact locations of things, just strive for a sense of things flowing about you as you walk. Try clicking your tongue. Do you hear the shifting directions and distances of things as you move among them? Mobility instructors may find that doing this at least once or twice a week will help them in sonar training with students, and to comprehend their own cognitive process struggling to integrate nonvisual information for efficient travel. Your students do this all the time.


                H. Try accompanying your better students under a blindfold in an area familiar to you. Practice sonar navigation with them. Let them help you. They will love it, and you will both learn something.