The Three Options of a Sound Wave

Any sound wave, upon striking an object in its path has the option to do one or all of the following three things:  Be reflected, diffused or absorbed by the object.

The type of object in question and the angle that the sound pressure wave strikes the object will determine what the sound wave does.  All of the sound energy will be captured by the sum of these three actions.  For instance, a signal emanating in a particular direction through air will be applying 100% of its pressure energy in that direction.  Once it hits an object, the sound will be reflected, absorbed, and/or diffused.  If you were to measure the amount of sound pressure energy in all three of these directions, it would add up to 100% of the initial sound energy.

Reflection

A sound wave that strikes an object perpendicular to a flat surface and bounces back toward the direction it came from has been reflected.  Glass, walls, water, and other hard objects are generally good at reflecting sound.  If the sound strikes the object at an angle, it will be reflected in the equal and opposite direction as light reflects off a mirror.  This suggests that glass and smooth surfaces can be difficult to see using echolocation unless you are perpendicular to a flat surface (See calibration surfaces).  When you are at an angle to the surface the sound reflects off in another direction and does not return directly to your ears.  This makes it much harder to see.

Diffusion

A sound wave that is reflected in many different directions at once has been diffused.  Sound is being scattered in all directions and therefore there is much less sound energy to any of the resultant sound waves.  This can make an object more difficult to see since the signal returned is not quite as "clear".  It sometimes sounds "muddied".  Tree bark or very rough walls are a good example of diffusive surfaces.

Absorption

A good percentage of sound waves hitting softer objects will be absorbed by it.  This means that the sound goes inside the pores of the object and expend their sound pressure energy before coming back out of the object.  A soft pillow, or clothing absorbs quite a bit of sound.  This, similar to diffusion makes objects more difficult to see and makes them less "present", or less "clear".

Echolocation Pushups?

I was doing pushups recently and noticed an interesting effect that you might want to experience on your own. I was breathing deeply as one tends to do under exertion and listening to the sound of my breath against the hard wood floor. As my body rose and fell and my face became closer and farther away from the floor, the reflection of my breath phased in and out like a musical instrument.

There's nothing unique about this exercise compared to any other beginner echolocation exercise. However, I think it's important to understand and practice using your own breath as a signal as opposed to a click. There are certainly scenarios and circumstances where a loud click is inappropriate, but ambient noise is generally much more challenging to use to see objects at any distance and even more difficult to distinguish detail from.

By learning how your breath sounds reflected off of objects may serve as a good alternative in a quiet environment if need be. The sound of a deep breath, either through the nose or the mouth, is remarkably similar to white noise which I discuss in greater depth in the book Beginner's Guide to Echolocation.

Basically, white noise offers multitudes of different frequencies, high and low which, as we know, all reflect off of objects differently. Some objects reflect higher tones, some lower tones. In some of the very beginning lessons we suggest using a "SSHH" sound to emulate white noise. Breath isn't as loud as making a "SSHH" sound, but in effect it is very similar.

Another interesting note about pushups is simply the fact that your echolocation target is moving in and out, in and out, over and over again. Even if you're not actively learning anything new by experiencing this effect, it's great practice, it's becoming accustomed and, little by little, getting more in tune with the subtleties of echolocation.

Visualizing the Sounds Around Us

When we echolocate, it's not necessarily important to understand the physics and psychology of what is going on, but for me, that level of detail is fascinating, and while I might not be able to readily apply it in daily practice, it's good to know what's going on behind the scenes.  And inevitably, we will find small ways of implementing these little bits of knowledge.  Understanding sound to a greater level will allow us to visualize exactly what is going on and will give us a more intimate picture of reality.

When we talk about the mechanics of echolocation, it's entirely comprised of sound waves.  Sound, fundamentally is fluctuations in air pressure.  These fluctuations happen fast enough for us to refer to them as "vibrations".   When I say a fluctuation in air pressure, that means a region of high pressure, followed by a region of lower pressure.  These pressures are so low, much lower than atmospheric pressure so we generally can't feel the sounds (although there are cases that sounds are felt and that is another interesting topic) but our ears are very sensitive to these very low pressures and can easily detect them.

When you emit a sound visualize waves of energy emanating from the source (your clapping hands, your mouth, etc.).  Depending on the shape of the object emitting the sound, the sound waves will be shaped differently in all directions.  Sounds coming from your mouth will generally be loudest in the direction straight out from your face.  A megaphone, for instance is not very loud if you were standing beside someone using it, unless they were to aim it directly at you.  The sound energy is much greater in that direction.  A clap will be much more uniform in all directions, however when the sound waves strike your body they will be reflected, absorbed or diffused and will change the sound pattern when observed from a wider perspective.

This is the same for any object.  Supposing a sound source emits sound equally in all directions.  The sound will radiate outward at a certain speed and strike the nearest object first.  As soon as it hits that object sound will stop travelling in that direction and the overall "soundscape" will be affected by that object.  The change in this "soundscape" would be another way to consider echolocation.  Once you start to consider all of the objects that the sound waves may contact during their journey and the infinite amount of interactions they can have, it becomes very interesting to try to visualize the shape of the emanating sound wave.

This is really neither here nor there, but an interesting thought experiment and something to ponder.  Let me know if this thought process leads you to any deep revelations.

Benefits of Echolocation for Blind Mobility beyond the White Cane

The cane is probably the most popular tool for blind mobility.  People who use it regularly are generally very comfortable with it.  As I attempt to introduce echolocation as a mobility tool I do of course meet resistance.  Many blind people are not comfortable with echolocation or don't see the benefits it can offer.  One of the most popular arguments against echolocation is "I can see everything with a cane that I could with echolocation, why would I want to go around clicking when the cane is perfectly socially acceptable?"

My answer to this is, you cannot see everything with a cane that you can with echolocation.  Let's take a close look at the difference:

One Data Point

In order to see an object with a cane you have to move the cane to the object, touch the object with the tip of the cane and then move your cane around to see other parts and other surfaces of the object.  It's safe to say that the cane provides only one "data point", meaning only one piece of information at a time.  It may take a few seconds to touch something in a few places and actually get an understanding of what it is.  Echolocation, on the other hand, offers several data points in a single click - an instant.  One click can uncover the shape of several surrounding objects.

Beyond the Tip of the Cane

The cane is a physical object about 4 feet long.  Essentially this is the range of one's perception.  If the cane is the only thing you are depending on to navigate.  Then anything greater than 4 feet away is completely invisible to you.  With echolocation the range of your perception can be up to several hundred feet.  You can see buildings, trees, people, hallways, entire rooms much larger than the length of your cane, and you can see them in an instant, or at least after a few clicks.

Side Vision

When walking with a cane, it is generally swung back and forth in correspondence with one's footsteps.  It is swung in an arc to determine anything on the ground within the walking path.  Unless you swing the cane way over to the side and try to touch something you will not see anything beside you.  Echolocation of course offers perception of objects on both sides of you, objects at head level, objects above you, and even behind you.

Physical Contact

Of course with a cane you must make contact with the object you wish to understand.  Sometimes that can be someone's shin, something fragile or something that causes a loud noise.  This can be arguably more intrusive than making a click sound with your mouth.  The only thing that makes contact during echolocation is sound waves which, to my knowledge, have never been observed to bruise shins.

It is encouraged that people supplement the white cane with echolocation and learn to use them both together because, while the cane acts as an excellent and irreplaceable safety device, echolocation gives you a much broader and more complete view of the world around you.  Echolocation isn't a huge life change you have to make all in one stroke.  It's easy, if you have an open mind and are willing to try new things, to take it a little bit at a time and experiment with it on your own to get comfortable.  And know that you never have to relinquish the security and assurance that your cane provides.

Another review for the Beginner's Guide

Here's another great review from Alexis Utica in Romania.  Read the whole review at:  http://www.humanecholocation.com/book-review-alexis-utica/

The book is a bold interpretation of echolocation, being the first book on such manner I find it to be very fun to read and understandable to any person who wants to discover this “sense” that we each have. The author introduces, during the lecture, motivational quotes by Albert Einstein, the Dalai Lama, Galileo Galilei and more, that make you feel that tiny boost of “Yes I can” into your life; I wanted to add this line because it made me want to read more and more with each paragraph.

Beginner's Guide to Echolocation - Audiobook Now Available!

The audiobook version of Beginner's Guide to Echolocation is now available here:

http://www.HumanEcholocation.com/audiobook

The audiobook includes click samples for use with echolocation and its impeccable audio quality and musical transitions make it easy and enjoyable to listen to.  Narrator, Gabriel Bush, brings his professional and powerful voice to this book to give it the impact and professionalism it needs.

Running Time:  2:17:07
Format:  MP3 Download
Author:  Tim Johnson
Co-Author: Justin Louchart
Narrator: Gabriel Bush

The book will soon be available on Amazon, Audible and iTunes as well.

Book Outline:

Introduction & Preface

Part 1 - Intro to Echolocation

Part 2 - Beginning Your Journey

Part 3 - Start Experiencing Echolocation

Part 4 - Echolocation Signals

Part 5 - Echolocation Lessons

Part 6 - Continuing Education and Training

"The world is full of magical things, patiently waiting for our senses to grow sharper."
William Butler Yeats

Echolocation F.A.Q.s

Here are some frequently asked questions about learning echolocation

Q: How long does it take to learn echolocation?

It all depends on how much time you want to commit to dedicated practice, but it is possible to learn a great deal in only a few days.  The three day intensive seminar through World Access for the Blind gives people the ability to comfortably navigate in foreign environments.  

Q: What's the best click to use for echolocation?

The click recommended for use with echo location by world access for the Blind is the blade pop.  There are also many other sounds that may be useful in other situations and environments.

Q: What is the best age to start training?

Young children tend to pick up echolocation faster then adults, but people of any age can easily learn echolocation.

Q: Why would I use echolocation when I'm proficient with a cane or have a guide dog I love?

It is true most blind people feel comfortable with one of these more conventional methods.  It is suggested that you use these conventional methods in conjunction with echolocation training.  The speed, range and versatility of echolocation offers great advantages over these conventional methods.  With a cane the knowledge of your environment is limited to the length of the cane and the speed at which you wield it.  Echolocation can give you instantaneous knowledge of everything around you within 100 feet, or even more.  A guide dog may be able to show you the way, but echolocation allows you to see the way for yourself.

Q: Can I learn even though I'm sighted?

Yes.  You will be at a disadvantage and it will take you longer, but if you can hear you have everything you need to learn echolocation.

Q: At what age can I start teaching my child echolocation?

If your child is blind they will naturally be exploring the sounds around them every day.  It's never too early, or too late to starting encouraging the concept of echolocation.

Q: What is the best way to start learning echolocation?

If you are blind or visually impaired and you have a mobility instructor, tell them you're interested in learning.  If you don't have access to a mobility coach, contact World Access for the Blind.  If you're not ready for dedicated training or would like more information about it, pick up the Beginner's Guide to Echolocation, available in large print paperback and audiobook.  If you're not ready to spend money on a book sign up for the mailing list and get a free audio lesson.

What Does a Non-Visual Image Look Like?

I've only started to scratch the surface of non-visual imagery, but this is one of the truly profound elements in the study of echolocation.  It's one thing to listen to sounds and think.. "oh that sounds farther away than this..." or "I can tell the doorway is here because it sounds hollow".  After a few years of my own intermittent training I have only begun to start to register non-visual images.  It doesn't happen all the time, but when it does it is a wonderful feeling.  A rush of excitement comes over me when my senses "open up" and provide this very clear "image" of the things around me.

Being a sighted person, it is certainly taking me longer to learn echolocation than it would for someone who is blind, so you may start to register non-visual images in a much shorter amount of time.  First this is due to the amount of time I can dedicate to practice, and additionally, my visual cortex is already very busy with my everyday vision to have room for such things as non-visual images.  It's known that an unused visual cortex can be re-commissioned to aid in echolocation, so you may have that to your advantage.

I have indeed experienced them and it is an absolute thrill ride when I get a "moment of clarity".  Basically, this involves being aware of the big picture as opposed to thinking so hard about the mechanics of it.

So what does it look like?

I would describe the feeling of a non-visual image to be a thought.  If you picture a shape or shapes in your mind, that might be akin to a non-visual image.  In our mind's eye, we can manifest an infinite amount of thoughts, places, shapes and images.  When echolocating we can still receive or create this type of imagery, but it will be based on our sensory input as opposed to our imagination.  So in that case, I would imagine that it looks different for everyone.

For me these images are comprised of two things:
1. Edges of objects
2. Proximity

Remember, there will be no color or text information supplied by echolocation.  Objects are outlined because of the sensation that there is a difference between one point and the next.  Generally the closer objects have a sense of being more dense, or thicker.  Sometimes that translates to being "darker" for me, but like I said, I'm sure it will translate to something a little bit different for each of us.

Have you had any experiences like this during your training?  Let me know about your experience with non-visual images in the comment section.

Tracking Along a Wall using Echolocation

Let's start moving!

As long as you're comfortable with Lesson #8, Seeing Right and Left, you should be able to start tracking along a wall or flat surface.  Try to find a wall that you are familiar with, it can be indoors like a long hallway or outdoors against the side of a building or solid fence.  It should be something that doesn't have a lot of other obstacles around, like trees or furniture or other objects and should be free of danger.  A straight stretch of wall with no windows or doors would be best.

I like to calibrate to my surroundings first by clicking around and getting accustomed to the environment.  Approach the wall first and click to echolocate the wall.  Turn one direction and then the other, still clicking to get a feel for what the wall looks and "feels" like.  Move toward and away from the wall and verify that you know how far from the wall you are by reaching out to touch it with your hand or cane.

Turn in the direction you are going to walk and get comfortable with the sound of the wall on that side of your body.  Once you are comfortable with the sensation of the wall, start walking alongside the wall and try to maintain the same sensation on that side of your body.  Move slowly if you need to at first, and remember, since you have already determined that the route is free of dangers, you should refrain from reaching out to touch the wall even if you think you are going to hit it.  If you get a strong "close" sensation on the wall side, just pause a moment and take a step away.  Gradually increase your speed as you become more comfortable doing this.

If you are in a hallway, you will have walls on either side of you which may be a bit easier because I think getting dangerously closer to an object is easier than detecting getting farther away from an object.  But the principle is the same either way.  Just try to maintain your proximity to the wall or walls.

A Few Advantages of Echolocation over Vision

Vision is mode of perception unlike any other; it provides so much information to us and is the primary sensory input for most people.  Using vision we can interpret 3-dimensional space and color to a great level of detail.

However, there are some benefits that echolocation can offer; details that cannot be distinguished using our eyes.  These benefits are, most notably:  Texture, Density and Material.

With our eyes we can make assumptions about these things based on prior knowledge, but they do in fact require that prior knowledge in order to make that assumption.  Our assumption will be base on what the object is, the reflectivity of the surface which in turn indicates the smoothness or roughness of the surface, and the color differences.  As is the nature of vision, however, it is always subject to optical illusion.  Things may appear to be one thing, but then turn out, in reality to be something completely different.

With echolocation the texture of an object can be seen as it is a direct result of the sound waves diffusing upon hitting the surface.  Much the same as with light, if you shine a flashlight in a mirror, you get a big bright dot in your eye, whereas if you shine a flashlight at a carpet, it diffuses and looks very different.  Not as much light returns to your eye because a good percentage of the light is being redirected toward other directions.  Since we are only one observer and our eyes and ears can only be in one place at any given time with respect to a signal, the texture of an object becomes apparent when we notice that the response signal is "softer" than it would be as compared to a hard flat ("shiny") object.

This is just one example of how echolocation can lend us advantages over vision, aside from the myriad of profound implications it has on the human race as a whole.

Another Great Book Review - Roger Wilson-Hinds from ScreenReader.net

A book review from Roger Wilson-Hinds of:

www.screenreader.net

It is a sad fact that the term echolocation is little known amongst blind people, never mind the main population. Johnson Is passionate about his subject and rightly so. To maximize the use of our senses is great and this is especially so if you lack an important one like sight. Echolocation is about getting the best from your ears. Hearing or sensing the detail of what is around, hearing there is a lamp post before you bump into it or being able to judge the size of the room you are in and knowing
how far off a wall is in front of you.

Those of us who have been privileged to work closely with blind infants know that they use their native wit and make clicking sounds within their mouths to help them understand their surroundings via the echos they get back in their ears. Johnson goes into the detail of the best way to click, the best frequency of the sound to make and later delivers an echolocation teaching programme. The fact is that anyone concerned to improve the lives of blind people should read this book and learn from it. And furthermore, as Johnson often says, the rest of us too  can do much to enhance our own control over the mind and senses  by spending time and effort developing our echolocation skills. After all, we as humans have massive redundancy of abilities which our ancestors needed but which have fallen into disuse or under-use.

A good read for anyone inquisitive about stretching human limits and overcoming disabilities.

Learn from Familiar Environments; Challenge Yourself with the Unfamiliar

I've recently had the good fortune of moving to a new house and with that comes the benefit of being able to navigate an environment that is not particularly familiar.  The more we become familiar with one certain environment, the less practice we get using actual active echolocation.  For instance, we may use clues to help us navigate, such as "the void" I know to be the 15 foot long hallway, or "the chair" I have to navigate around.  Once we place ourselves into a foreign environment, it becomes much more critical that we actually concentrate and utilize precise active echolocation.  This is a good thing because it forces us to get better.

Instead of saying to yourself, "oh yes, and there's the table.. and if I go this way I can go around it safely..." you're forced to ask, "...and what is this object here?  ...and how can I go around it?"  In this case, your mind will really be required to focus in and you might try clicking at different angles or moving from one side to the other to get a different vantage point.  You might even crouch down to check the height of the object (avoiding the urge to reach out and touch it).  All of these exercises are critical learning methods for improving your skill.

In other instances, you might say to youself, "OUCH!  That really hurt... what the heck was that?"  In which case, that's not always a bad thing either.  In instances of pain, since we are human beings we will try to avoid repeating that same scenario at another time, and one natural way of doing that is to take inventory of the situation and say to yourself.. "Why did that happen?  What did I miss?"  At which time it would be a good idea to take a step back and evaluate the current environment as in the paragraph above and try to determine the reason your echolocation did not show you that particular object.  If it was something at waist level, then that might indicate that you need more practice with "Up vs. Down Training".  If the object was a thin object like a lamp post or pole, consider isolating that type of object and challenging the limits of your echolocation in order to improve your capabilities with such object shapes.

The moral of this post is, always challenge yourself.  Now, is training in your own home cheating?  I would say no.  But if you become complacent in a particular environment, you are inherently not challenging yourself as much as you could be, do some exploring!!

My first book review from Austin Seraphin!!

I'm so happy to announce my very first book review of the Beginner's Guide to Echolocation!  Austin Seraphin is a great guy and many of you know him I'm sure.  He just wrote a great article covering his thoughts on the book over at his blog "Behind the Curtain".

Here is a snippet of the review

I have some very exciting news. Ever since I started learning about echolocation I wanted a way to get started myself. I made contact with Justin at World Access for the Blind and he helped me on Skype before we did my amazing life-changing intensive. Still, we all agree that we need a way to easily teach the blind about echolocation, or at least give them enough information to get them started safely. We also need to prove to the skeptics that it really exists. Now someone named Tim Johnson has written the perfect book to get you started.

Read the whole review here because he has some great things to say that I'm sure you can relate to.  I'm so glad that this book is being well received.

Of course if anyone else out there is interested in writing a review of the book either on your blog or on the Amazon page, PLEASE contact me!  I will see what I can do about getting you a review copy of the book.

Echolocation Audiobook Coming Soon!

Okay, I will get back to writing posts you actually want to read very soon about my echolocation journey, but I'm very excited about the new book so I have to let you know that I am currently producing an audiobook!

I just found a GREAT narrator for it and it is being produced as we speak! (or type and read) It will be available on Audible.com, Amazon and iTunes within the next couple weeks!  Be sure I will let you all know as soon as it is available.

Also the Future Reflections publication has requested a copy of the book for review.  They are affiliated with National Foundation for the Blind and their review should be published in an upcoming edition of their newsletter.  So if you get that keep your eyes peeled.

Accessible Format Now Available: Beginner's Guide to Echolocation

I originally started this blog to simply document my findings in echolocation and my own experimentation, but it has long since evolved into something much more and I while I don't consider myself a mentor to anyone in the blind community learning echolocation, my articles here have been referenced by many people around the world looking for more information on the subject.  Many of these people are part of the blind and visually impaired community, and in an effort to make my new book Beginner's Guide to Echolocation for the Blind and Visually Impaired accessible to everyone I am working on offering it in many other accessible formats such as audiobook, text for screen readers and possibly Braille.

The first fully accessible version of this book is now available in simple MS Word format.  You can download this accessible file here:

MS Word format - Accessible version of "Beginner's Guide to Echolocation"

Spreading the Word of Echolocation to the Masses

Each day when I wake up, I tell myself that I will be a better person than I was the day before - I will improve everything that I do.  And to me, being a better person includes helping others, teaching others something new that can change their life.

That is the goal for my new book Beginner's Guide the Echolocation.  If I can help one person to live a better, more fulfilling life I will have done my job.

Echolocation has long been unnoticed and under-utilized, largely because it is misunderstood.  I think the largest hurdle in echolocation right now is simply spreading the word.  There's no doubt to those who use and understand it, that it works.  It works amazingly well and there is nothing else like it.

Having spent time learning the skill, I know it's not hard to learn.  Anyone can do it, and you probably do it more than you think.  There are so many people out there who would probably love to learn but they're embarrassed to!  The skill is not socially acceptable and that is one of the main reasons people don't want to learn.  So we can approach this problem from two angles:

1. Tell people to suck it up and do it anyway, all the while feeling like fools and potentially being outcast and sneered at.
2. Or increase awareness of echolocation worldwide which will give people less reason to sneer and snicker.

Of course option one is faster.  I still believe in option one and at this point in time, if you want to learn echolocation that may be what you have to do.

Option 2 on the other hand is the more complete, more sustainable way of approaching this problem.  If we expose echolocation for what it is, get it in the media, get it in books and in people's minds -- if we make it part of their vocabulary, and a household word, people will be far less likely to sneer.  They will at least be able to say "Oh that dude is echolocating, weird...".  And people might respond that way for some time, and after a decade or so, people will start to say "Hey I've seen a lot of people doing that, must be working..."  And of course after another decade, a skeptic of today might start to say "That's really incredible how you can do that.  Can I learn?"

Given the practicality of the skill, (especially for the blind, but even for the sighted) it is inevitable that it will catch on.  I know that.  I want to be a contributor and help it catch on, and that's why I've written the book, to expose it and get people thinking "Hey, I can see how this might be useful for a lot of people."

Beginner Echolocation Lesson #9: Seeing Objects From Above and Below

This is slightly more difficult. The ears are positioned on the side of the head, so right to left differentiation is easier than up and down. Right to left relies on the difference in amplitude or volume between the signals coming in each ear. The ability to differentiate between sounds from above and sounds from below relies primarily on the shape of the ear and the ear canal making it a bit more ambiguous. However, your brain already knows how to do this, so trust it.

If being able to distinguish right vs. left increases your echolocation "resolution" in the "X-axis" (or along the horizon) being able to distinguish up vs. down, will help you improve your resolution in the "Y-axis" (or vertically).  Each one of these resolutions will become very important when we start getting better and are able to start being aware of the non-visual images that our brain is creating.

1. To begin, in a quiet environment have a partner make a sound in front of your face, but slightly above it at about a 45-degree angle upward. Have them rub their fingers together gently to create a very quiet sound. 
2. Have them move their hand below your face, to about a 45-degree angle and make the same subtle sound. This will give you a frame of reference for echolocating to these two positions.
3. Now have them hold up your hard flat object in these two locations. Use your click signal and learn to sense its direction the same way you sensed the direction of the sound they made with their hand. At this point, have them tell you which position it’s in.  IE: "the object is in the upper position" (and click to calibrate to it) and then "the object is in the lower position" (again click to calibrate)
4. The next obvious step is for them to randomly change the location of the object and have you distinguish the location by pointing up or down. It’s important that they confirm your answer so that you can learn when you make a mistake.
5. If this exercise proves to be difficult, simply move the object closer to your face until it becomes apparent. From there you can gradually have your partner move it away as you become more comfortable.

The reason we start in such a controlled environment is to isolate variables and make the signal and response from the object as apparent as possible.  If there are lots of other objects around or lots of noises in the background this will certainly make it a lot harder especially when you're just starting out.

Beginner's Guide to Echolocation - NOW AVAILABLE!

I'm happy to announce today that my book, The Beginner's Guide to Echolocation is now available in large print paperback edition on Amazon, Amazon Kindle for your e-readers, MS-word format for blind accessible screen readers, and also audiobook format.

Here is a synopsis of the book:

What is Echolocation?

The ability to "SEE" objects using sound instead of sight.

Echolocation is a fundamentally simple skill that many blind people use daily to navigate and understand their environment. This skill is sometimes misunderstood, but it’s far more realistic and much easier than you may think.

The author demystifies the growing practice of active echolocation in a way that anyone can understand, and gives the reader simple exercises, examples, and lessons as a starting point for launching you into a successful practice of active echolocation.

Sound waves – like ripples in a pond – reflect differently off of all objects and surfaces. This makes it possible for the trained ear to distinguish shape, size, distance and material of our surroundings. Musicians will tell you that “reverb” causes each room or surface to have its own unique sound response. With sensitization and applied practice of this skill, it’s possible for people with visual impairments all over the world to become increasingly independent, supplementing their existing forms of orientation and mobility with the intrinsic awareness that echolocation can provide.

Echolocation requires no special equipment nor any special talent. The human body and mind are truly marvels of nature that grant us with capabilities you may never know you had. If you can hear, you can echolocate.

Understanding the simplicity of this skill will allow you to shift your way of thinking to accommodate an expanded awareness of your environment. With this awareness comes independence, confidence, new possibilities and new opportunities.

Get your copy on Amazon here

Listen to a free sample of the audiobook version here.

A Common Use of Echolocation: Ultrasounds

I like being able to offer real-world examples of how the concept of echolocation is being implemented in our daily lives and in the technology around us.  Submarines use echolocation to navigate and are essentially blind vehicles as I discussed in a previous post.  I came upon another implementation of echolocation recently after my wife and I found out that we are going to be parents!

An ultrasound machine, used for creating images of unborn babies inside of the womb, uses the concept of echolocation to a large degree.  Ultrasonic sound waves are emitted from a device into a woman's womb and the reflections of the sound are then analyzed by the machine and interpreted into an image that can be viewed on a screen.  These images are a representation of tissue densities at certain depths.   The thicker tissues reflect more sound and therefore create a different color on the screen.  When all of these little finite bits of information are pieced together they make what is known as the ultrasound image.

If any of you have been witness to this first hand, you'll know that it's an incredible thing to see.  A moving picture of your unborn baby.

This works in much the same way as echolocation.  Millions of bits of information from reflected sound come into your brain and are processed to create an image.  Fortunately for you, unlike the computer version of this, you don't actually have to do any math!!  Your brain is able to calculate and interpret these findings in a completely natural way allowing you to get the same result without doing all the work that the computer has to do.

Beginner Echolocation Lesson #8 - Seeing Right and Left

To begin determining direction and placement of objects around you, one of the skills you will need is to be able to differentiate between objects to your right and objects to your left.

1. With a partner, start by using a dinner plate or similarly sized rigid sheet of plastic, metal or wood and have your partner hold it up to one side of your head. Perhaps not directly on the side, but out in front of you to the right or left at about a 45-degree angle. 
2. If you are sighted or partially sighted, of course you'll need to close your eyes or wear a blindfold.
3. Instruct your partner to move it to within 12 inches of your face, and then without notice, remove it from your view. Keep clicking or performing whichever signal works best for you.
4. For this exercise, the flat surface of the object should always be facing directly toward you. This will ensure that the strongest, clearest response is reflected back toward you. 
5. It is important that the object you are using does not make any noise of its own, such as the pages of a magazine. It’s also important that the person holding the object does not scratch or manipulate it in such a way that makes any sound. This will defeat the purpose of the exercise. 
6. Once you can clearly tell when the object is present and when it’s not, try it on the other side. 
7. Get used to both sides and then have your partner surprise you. After a short period of training, you should be able to easily determine where the object is.

Why Learn Echolocation as a Sighted Person?

The benefits of acquiring the skill of echolocation as a blind person have obvious impact to the way you interact with your surroundings on a daily basis.  Any insight that echolocation can offer adds incremental information directly to your perception.

As a sighted person, to train echolocation, you must close your eyes.  This is inherently reducing your amount of perception and starting at a level that you are not comfortable with and you may have very low confidence navigating in the dark.  So why would you want to learn??

I asked sighted people in a survey why they wanted to learn echolocation below are some of the common responses:

• To continue my life normally if I ever were to lose my sight.
• To continually and aggressively exercise my brain.
• It's a fascinating subject and an interesting skill to learn.
• I'd like to be able to navigate in the dark better.
• To aid in understanding of visually impaired people whom I work with.
• And many other good reasons along these lines.

Personally, I can come up with a thousand ways echolocation can benefit sighted people... okay maybe not thousands... but at least a few.

In today's world people are becoming more and more open to exploring new methods of learning and growing as a society.  This blog is a good example of that..  I can put this very obscure information out there on the web and there are hundreds even thousands of people who read these articles and respond to them with their feedback and stories about how they are learning echolocation.  It's wonderful to see so many people opening their minds to new possibilities and seeking out new challenges.

Working the brain muscle is always a good thing to do.  Things like learning new languages, learning a musical instrument, learning to cook or learning how to juggle or otherwise improve your coordination is great medicine for the brain.  Notice how each of these examples starts with the word "learning"?  See a pattern?  Learning echolocation is, of course, great brain exercise, but the fact that echolocation is likely to be a completely foreign concept requires entirely new channels to be opened in the mind.

Eventually, not this decade and probably not this century, but eventually, I'm certain that echolocation will become a mainstream mode of perception for all humans.  It will be taught from childhood and will have several applications in daily life.  It can help us become a better race and a better society.  This is the natural way of evolution and new skills like this have been added to the human skillset for thousands of years.  We will always continue to grow and develop as a species.  We can be a little ahead of the curve and essentially see into the future by recognizing these skills now and being part of the driver that helps them propagate to future generations.

Everyday we should challenge ourselves.  This is the only way to improve ourselves.  Each day that passes without overcoming adversity or learning something new or standing up to face a new challenge is a day wasted.  A phrase that we would recite in Portuguese at the beginning of a martial arts class I took was: "Each day that passes, I am improving everything that I do."  Every day I want to become a better person and challenge myself in ways that I did not challenge myself the day before.  Echolocation is a great new horizon on which I find many challenges, and it is for that reason that I find it so alluring.

Matthias' Journey into the World of Echolocation

Through one of my acquaintances at World Access for the Blind, I recently found this new blog from the mother of a blind child named Matthias.  Matthias is 4 years old and completely blind and he has recently been introduced to echolocation by taking a 4-day workshop with Justin from World Access.  This article on the blog explains the experience of having Justin to the house and how receptive Matthias was to the training..  It's quite humorous and well written.  I would suggest that everyone interested in echolocation training for children subscribe to this blog because there is sure to be more interesting insights coming from it as Matthias improves his skill.

His mother (after reading several posts I still can't figure out her name; it might just be "I") also has a YouTube channel with great videos of Matthias learning echolocation by playing simple games.  One of those videos is here:


I love seeing young kids like Matthias learn echolocation (whether they resist learning at first or not) because I'm sure it will change his life for the better.  Per the blog post here entitled "Echolocation... because our son is smarter than a bat", Matthias has already begun to increase his walking speed which was troubling him, so that he can better keep up with his friends and play games.

Way to go Matthias!  Keep up the good work!

Frequency Absorption Characteristics of a Variety of Materials

In order to understand a topic fully, it's important to deviate sometimes and uncover bits of data that are not necessarily contributing toward our physical training or implementation, but instead, add to our overall understanding of a subject.  Whether or not you actively utilize this information during your echolocation practice is not important, however it is important to understand and acknowledge it.

In this case, I would like to take a look at how different materials absorb different frequencies.  This will help you to understand how softer items, like upholstered furniture, might differ from doors and how doors differ from concrete.  The numbers listed in this chart are the "absorption coefficients" of these materials.  

To give you an idea of how it works, carpet, the first item on the list has an absorption coefficient of 0.01 for 125Hz frequencies.  That means that it will only absorb 1% of a tone at a frequency of 125Hz.  It will absorb 2% of a 250Hz tone, 6% of a 500Hz tone, 15% of a 1kHz tone, 25% of a 2kHz tone and 45% of a 4kHz tone.  

It becomes easy to tell that some materials absorb a good percentage of some signals, but reflect a good percentage of other signals.  Remember that any percentage of the signal that is not absorbed is reflected.

The reason we start learning echolocation using hard flat objects is because of the fact that, as you see below, things like glass only absorb 2-3% of most frequencies and are therefore very reflective, or responsive.  As opposed to things like upholstery and people which absorb at least 25% of most frequencies, and up to half of some of the higher frequencies.

Material 125 Hz 250 Hz 500 Hz 1 kHz 2 kHz 4 kHz carpet 0.01 0.02 0.06 0.15 0.25 0.45 Concrete (unpainted, rough finish) 0.01 0.02 0.04 0.06 0.08 0.1 Concrete (sealed or painted) 0.01 0.01 0.02 0.02 0.02 0.02 Marble or glazed tile 0.01 0.01 0.01 0.01 0.02 0.02 Vinyl tile or linoleum on concrete 0.02 0.03 0.03 0.03 0.03 0.02 Benches (wooden, empty) 0.1 0.09 0.08 0.08 0.08 0.08 Benches (wooden, fully occupied) 0.5 0.56 0.66 0.76 0.8 0.76 Theater seats (wood, empty) 0.03 0.04 0.05 0.07 0.08 0.08 Theater seats (wood, fully occupied) 0.5 0.3 0.4 0.76 0.8 0.76 Seats (fabric-upholsterd, empty) 0.49 0.66 0.8 0.88 0.82 0.7 Seats (fabric-upholsterd, fully occupied) 0.6 0.74 0.88 0.96 0.93 0.85 Brick (natural) 0.03 0.03 0.03 0.04 0.05 0.07 Brick (painted) 0.01 0.01 0.02 0.02 0.02 0.03 Concrete block (coarse) 0.36 0.44 0.31 0.29 0.39 0.25 Concrete block (painted) 0.1 0.05 0.06 0.07 0.09 0.08 Concrete (poured, rough finish, unpainted) 0.01 0.02 0.04 0.06 0.08 0.1 Doors (solid wood panels) 0.1 0.07 0.05 0.04 0.04 0.04 Glass (1/4" plate, large pane) 0.18 0.06 0.04 0.03 0.02 0.02 Glass (small pane) 0.04 0.04 0.03 0.03 0.02 0.02 Drapery (10 oz/yd2, 340 g/m2, flat against wall) 0.04 0.05 0.11 0.18 0.3 0.35 Drapery (18 oz/yd2, 612 g/m2, pleated 50%) 0.14 0.35 0.53 0.75 0.7 0.6 Performated metal (13% open, over 50mm(2") fiberglass) 0.25 0.64 0.99 0.97 0.88 0.92 Wood tongue-and-groove roof decking 0.24 0.19 0.14 0.08 0.13 0.1 People-adults 0.25 0.35 0.42 0.46 0.5 0.5 People-high school students 0.22 0.3 0.38 0.42 0.45 0.45 People-elementary students 0.18 0.23 0.28 0.32 0.35 0.35 Ventilating grilles 0.3 0.4 0.5 0.5 0.5 0.4 Water or ice surface 0.008 0.008 0.013 0.015 0.02 0.025

Source: http://www.sae.edu/reference_material/pages/Coefficient%20Chart.htm

Why a 3kHz Frequency Tone is Optimal for Echolocation

Below is a representation of the human hearing threshold which gives us a good idea as to why a 3 kilohertz (kHz) beacon signal is a good signal to use for echolocation.

This chart is plotting the intensity in decibels that is audible by the human ear at different frequencies along the audible spectrum of sound.  Additionally, the different lines represent different signal "loudness levels".  At lower frequencies, and lower loudness levels it becomes increasingly difficult to differentiate between tones. The lower tones, near 20 Hertz are only audible once they reach approximately 75 decibels (dB), which means that a low tone needs to be far more powerful to be perceived.  

There is a consistent dip around 3kHz where it is indicated that softer sounds are perceived just as well as other frequency tones of the same loudness.  As signals get higher in frequency, it is required again that they be of greater loudness in order to be perceived at the same level.

This has to do with the construction of the human ear canal.  A 3kHz frequency resonates nicely in a 2.4cm tube at body temperature, which is the average size of an ear canal.

Source:  http://hyperphysics.phy-astr.gsu.edu/hbase/sound/eqloud.html#c1

We have to remember however, that a single frequency tone is not entirely optimal due to other circumstances.  For instance, a 3kHz tone may be completely absorbed by an object.  Fiberglass boards appear to absorb these frequencies very efficiently, as well as upholstered benches according to this absorption coefficient chart.  For this reason, it is important to choose a signal that consists of a broad spectrum of frequencies.

The Presence of a Curbstone - Starting to get a "feel" for echolocation

The other day in an outdoor training session, I had another amazing revelation that I want to tell you about.

With my eyes closed, I was sighting buildings, trees, parked cars, a couple signs, and so forth and feeling pretty confident and relaxed.  I was opening my eyes every so often just to calibrate my sensation to my surroundings.  This gives me an idea of what to expect around me after I close my eyes, but if I keep them closed for long enough, my immediate orientation and short term memory is not enough to keep me oriented without the use of echolocation.  You can read my post on walking a predetermined path for more on that.

During one of these calibrations with my eyes open, I noted that among other buildings, trees and cars, there was a curbstone present in the distance.  Something I generally pay attention to as a precaution, since these are easy to trip on and very hard to see with echolocation.  But I closed my eyes and continued on following about 40 feet from a large building through a rather empty parking lot.  After going quite a ways and passing the corner of the building, I was aware that the curbstone would be approaching shortly on my right hand side, I directed my attention downward and actively clicked in the direction I anticipated it to be.  Not expecting to see it, but rather as a reminder to myself to be cautious of that area.

Low and behold, after a few clicks an actual presence emerged from the flatness of the parking lot and something appeared before me.  The pavement around me was all so flat, that the curbstone was actually noticeable.  But instead of "hearing" the curbstone, it just stuck out to me as a "presence" or another moment of clarity.  It was simply the "knowledge of an object" on the ground or "change" of some sort.  I guess you could call it a ripple, which technically a curbstone is.

This gives me some insight and understanding of what it will be like to use echolocation as a natural "sensation" and start "feeling" it as opposed to constantly thinking about it.

Anyhow, I thought this was fascinating and worth sharing here.  I think the fact that I was fairly relaxed helped this object to pop out of the darkness and show itself to me.  Also, my training session had been going on for quite a while and I was getting used to walking around with my eyes closed.

If you've had any experiences like this, let me know :)

Outdoor Echolocation Training Session

In my office park during my lunch break I tend to walk aimlessly around the parking lot and grassy open space just to get a little vitamin D (sunshine) in the middle of the day.  There are many trees, large buildings, cars, bushes and other interesting obstacles that allow me to practice echolocation.  This gives me an opportunity to walk places that I am not familiar with and practice different types of clicks, different volumes, different head postures, etc.  I generally sight a target in the distance and then navigate my way to it.

I've had good success with the large buildings.  I can see when they start and stop as I walk beside them, and I can judge their distance up to about 30-40 feet away.  Further than that I can tell there might be a building there, but probably wouldn't be able to accurately judge the distance.

Trees are good targets, I generally attempt to make a tree my target from 40-50 yards away and locate it.  Of course since trees are round, the response signal that will be reflected back to you will appear narrower than the actual tree.  This is because a lot of the signal sound that strikes the tree near the sides, just glances off of it and does not properly return to your ears.  The signal sound hitting the centerline of the tree will be reflected back to your ears nicely and it will taper off as it approaches the sides.  For this reason I like to choose large trees as they will have the best response.  Another good reason to choose a tree as a target is that since they are round, they look the same from all angles, as opposed to a car, or building.  So it is possible to walk up to a tree and circle around it using echolocation.  Circling an object is a good way to verify that you are well aware of the size, shape and location of an object without taking off your blindfold, opening your eyes, or using your cane (whichever your case may be).

Undoubtedly, you have some sort of outdoor environment that you can use to train echolocation.  I would encourage you to simply explore at your own pace.  Make mistakes, but be sure to stay just within your comfort zone, only straying for your comfort zone when you know you are in a safe environment and when you have calculated all of the potential misfortune that environment can present.  Find targets, find routes, explore new sounds, new techniques, use some of the intermediate lessons and suggestions on this blog if you want to, but most importantly keep an open mind and OBSERVE!  It's not imperative that you walk away from each session with something concrete that you have learned, but it is important to enjoy the learning process.  The skill will come with time if you allow it to.

Make Calculated Mistakes!

One of the most important aspects of learning new skills that most people neglect is the power and beauty of the mistake. When a mistake occurs there is a profound moment of pure learning that you will not find anywhere else. I’m not saying take a running start for the stairwell here; calculated mistakes are the best. Make mistakes in a place where you can estimate the severity of the outcome of the mistakes and where you have an exit strategy in order to maintain your personal safety.

For instance, protect your toes. Objects near your feet can be hard to perceive, so wear shoes that allow you to kick things like curbstones and end tables without being injured. Wear a visor cap so that your nose or forehead isn’t the first thing to smack into low-hanging tree branches or shelves. Another option would be to have a sighted guide act as a spotter just to notify you of impending danger. 

Once you have addressed your personal safety and feel that you understand the severity of the potential hazards around you, it’s time to make mistakes. 

In order to improve your current physical and mental limitations you will need to push your limits. Your physical and mental limitations are generally governed by your level of self-confidence. In order to challenge and exceed those limits you will essentially need to be over-confident and fail. This will allow you to first, understand the limitations, and then figure out how to exceed them. Determine the little things, the details that you can adjust or focus on in order to improve your ability to echolocate. 

Now that you are ready to make mistakes, you are ready to begin experiencing echolocation.

Hearing Meditation to Increase Sound Sensitivity

Meditation has been used for thousands of years to increase awareness and can be used prior to echolocation practice to help open the mind and become more sensitive to intricacies of your “soundscape”, or the sounds around you. The goal is simply to listen intently to everything around you and process it all at one time. In essence, hear all the sounds around you as if they were all one sound. Essentially, they are. The vibrations that have come from each object, event or person making sounds all culminate in your ear drum as one finite amount of fluctuating pressure that is then registered by your brain. Your brain will work hard to process this one sound and break it up accordingly, based on where it knows the sounds to be coming from. The brain will break up the clock from the birds, from the wind, from people talking, your own breath, etc. Let’s give the brain a break for a moment and just experience the raw input of sound pressure coming into the ears.

First, sit in a comfortable place, in a position that suits your body – sitting, kneeling, lying down etc. Before “trying” anything, just take 10 deep, relaxed breaths and let your heart rate slow down as you relax and find comfort in your seat. Then start listening for all the sounds you can hear. It’s okay to focus on the sounds one at a time to start – in fact, focus on the loudest sound you can hear, and then find the second loudest. Count as many sounds as you can in the order that you notice them. Once you have found the next slightly quieter sound, listen to it for 20-30 seconds and then scan for something even quieter or more distant. This exercise will sensitize your ears and help you increase awareness of your environment.

After finding as many sounds as possible, now try listening to them all at once. Try to stop thinking “that’s the clock” or “there goes another car”, just be mindful and allow them all to congeal as one sound wave and listen to that sound wave. Once you have come to allow all of the sounds to come together, it should seem more like a song than each of these things individually. This song is a representation of the power of the current moment. By listening to this song you will start to realize the power in every moment throughout your day. Each moment is powerful in its own way, and it is up to you to realize that and make the absolute best of it. Don’t spend more than 5-10 minutes doing this as it is easy to lose focus unless you are accustomed to longer meditation. In addition to helping improve and sensitize your ears, hearing meditation can be otherwise very rewarding in that it can give you a sense of relaxation, focus and confidence. Being mindful of yourself and your surroundings can eliminate attachment to physical things and emotions that may be connected with people and things around you. Release all hatred, resentment, frustration, longing, pain and suffering and consider the beauty of the present moment and the “song” that describes it.