Human Echolocation - A How-To Guide

Five Senses and Nine Planets... Right? I Disagree.

noreply@blogger.com (Tim Johnson) — Thu, 10 Nov 2011 11:30:00 +0000

Everyone knows about the "Five Senses". We're taught at a very young age to understand these five basic input methods and to utilize them the best we can in our daily life in order to best understand the world around us:

Sight

Sound

Smell

Taste

Touch

Sometime what we learn in school can be limiting, however. Especially things that we learn at a very young age and, for the remainder of our lives, believe to be true. When I was little I was also taught that there were "Nine planets"... that has been the topic of several astronomical discussions over the past 10 years or so, and it is clearly an issue of the actual definition of the word "planet". No one wants to add more planets to the "line-up" just because there's... only supposed to be nine!

You see what I'm saying, right? It's a social, sometimes psychological struggle to shift one's paradigm from believing one thing, to believing something different. Once a belief, or a fundamental understanding of something is ingrained into our minds, it can be VERY difficult to change that belief.

I believe that there are more than five senses. And before you go directly to the comments section for your rebuttal, hear me out. Again, this debate will lie in the definition of the word "sense" and whether or not each "sense" has a dedicated organ. But to me, a sense can be related to a "channel" for information input, not necessarily an organ.

Some other senses I believe that we, as a human race, have and should be exploring and encouraging are:

Echolocation

Proprioception

Interoception

Equilibrioception

Pressure

"Extra" Sensory Perception (ESP)

Echolocation - Obviously, this is the first one I'm going to discuss. As far as organs go, this sense uses primarily the ears, but I believe it also uses the nervous receptors in the skin as well ("touch"), as vibrations and pressures from sound can easily be felt on the skin.

Proprioception - This is the sense of the physical positioning of one's own body; joints, limbs, orientation, etc. We talk about this in depth in martial arts classes. If you close your eyes and move your arms around, you have the sense of where they are. It's an interesting sense and you can read more in this article on proprioception written by Bruce Lee's daughter, Shannon. Some people have been known to lose this sense due to brain injury or other trauma and it is completely debilitating.

Interoception - This is our sense of the physiological well-being of our bodies. It's how we sense our stress levels, our mood, disposition, etc.

Equilibrioception - Our sense of balance, called equilibrioception, makes use of our eyes, ears and sense of proprioception, above.

Altitude - When we have a head cold our ear drums generally are generally very sensitive and can even pick up on slight pressure changes due to altitude. A similar feeling can be experienced when scuba diving as the water pressure changes when you dive deeper. Didn't think you had a built in altimeter (or depth meter) did you?

ESP - An amazing sense that may be controversial and experienced differently by different people. I know I've experienced certain intuitions that I can't describe. I believe that information can be transmitted many other forms. What are your thoughts?

I think this list is probably the tip of the iceberg and if you can think of more, please post in the comments!

I think it would be best to teach children about the "Senses" as opposed to the "Five Senses". This would eliminate the psychological limitations for future generations. If a new sense, is discovered, or developed, it would be in our best interest as a species to teach and further develop that sense.

Learning Echolocation - A Moment of Clarity!

noreply@blogger.com (Tim Johnson) — Fri, 05 Aug 2011 14:25:00 +0000

In my daily echolocation training, I routinely close my eyes while walking down the hallway in my office building. It helps when it is very quiet and there aren't any other people walking around (for many reasons..). Generally I just allow my ears to open up and notice the differences in the sounds depending on where I am in the hallway, what type of pants I'm wearing (I find that my pant legs brushing against each other actually act as a pretty good beacon sound), which shoes I'm wearing, weather I'm walking on a carpeted or non-carpeted area, etc.

After becoming aware of these subtleties, you can start to realize where the walls are by the sounds reflecting from them. It's not too hard to be able to stay aligned in the middle of the hallway using this basic echolocation method.

Today I had a bit different experience. In my building, there are several bends in the hallway which are generally more difficult to detect. A right angle turn is easy, because you will suddenly notice a "hollow-ness" off to one side and you will know that the hallway opens up to that side. However my hallway has several 45 degree bends which are much more difficult and I generally am too confused by the signal change to know exactly when the turn is coming. Today as I approached one of these 45 degree hallway bends I kept an open awareness to all of the signals coming in, but tried not to think about it too much. When I did this and approached the bend, I felt a complete shift in my subconscious understanding of where I was. It was as if the whole environment shifted around me. I actually felt the walls and I felt the opening ahead of me simply change position. My body understood the change and almost automatically course corrected.

I think something I've been struggling with is over analyzing the actual science of what's happening and not just being aware of the big picture. Today I learned that it's easy to over analyze and start thinking about all the actual sounds instead of just feeling your surroundings. Try not worrying about the details so much and just "relax into it".

I'm certain that confidence played a role in being able to ignore some of the details and relax, so it's still important to simply close your eyes and walk around even if you have no sense of echolocation and have no idea what you're listening for. This will help build the confidence and comfort level of walking with your eyes closed and eventually lead to the ability to relax.

Good Luck! Let me know what you find!

The Science of Echolocation in Bats - Active Sensing

noreply@blogger.com (Tim Johnson) — Wed, 22 Jun 2011 20:10:00 +0000

Followers! I just found this great publication from Nachum Ulanovsky at the Weizmann Institute of Science. It was just published this past May and has some great information on the physics of object recognition, texture recognition, beacon signal mechanics, the radar equation and all sorts of other fun stuff. So forget the books I posted earlier today, CHECK THIS OUT!

Active Sensing: The case of echolocation in bats

Echolocation Books:

noreply@blogger.com (Tim Johnson) — Wed, 22 Jun 2011 19:51:00 +0000

Sorry I've been slacking off here. For everyone out there looking for more information on echolocation check out these:

Listening in the Dark: The Acoustic Orientation of Bats and Men

Echolocation in Bats and Dolphins

The Sonar of Dolphins

ABC News Specials Medical Mysteries Series-Episode #3

Echolocation in Whales and Dolphins

The Neural Basis of Echolocation in Bats (Zoophysiology)

Echo-location

Perception: Philosophy of perception, Illusion, Déjà vu, Direct realism, Gestalt psychology, Animal echolocation, Chemotaxis, Nothing

Transmitting Beam Patterns of the Atlantic Bottlenose Dolphin (Tursiops Truncatus) : Investigations in the Existence and Use of High Frequency Components Found in Echolocation Signals

Echolocation: "A New Way of Seeing the World"

noreply@blogger.com (Tim Johnson) — Tue, 19 Oct 2010 12:02:00 +0000

Science Daily on echolocation:

this would be a new way of perceiving the world

I recently found an encouraging article published by Science Daily. This article introduces the concept of echolocation to the masses, and presents it in such a way that reveals entirely new possibilities for the human race. In addition to the benefits that I've been describing here, they discussed the potential use for echolocation as a sort of natural "x-ray".

The article discusses the capacity for anyone to be able to learn echolocation. This skill is not something you're born with and it's not something that's outside the realm of possibility. Like anything else, it just takes practice:

...no special physical skills are required in order to develop this skill. “Two hours per day for a couple of weeks are enough to distinguish whether you have an object in front of you, and within another two weeks you can tell the difference between trees and a pavement”, Martínez tells SINC.
The scientist recommends trying with the typical “sh” sound used to make someone be quiet. Moving a pen in front of the mouth can be noticed straightaway. This is a similar phenomenon to that when travelling in a car with the windows down, which makes it possible to “hear” gaps in the verge of the road.

Echolocation could rival sight itself

I love reading articles like this. There is so much more to the human machine than we currently know. This type of insight is sure to bring about a whole new perspective on life. This is another quote from the article regarding the potential use of echolocation for seeing through softer materials to the harder materials behind.

Another of the team’s research areas involves establishing the biological limits of human echolocation ability, “and the first results indicate that detailed resolution using this method could even rival that of sight itself”. In fact, the researchers started out by being able to tell if there was someone standing in front of them, but now can detect certain internal structures, such as bones, and even “certain objects inside a bag”.

Hopefully this type of research will continue and we can begin to develop this skill in our youths to give them a better understanding of the world, a leg up on all those who simply rely on sight, and the confidence of being an extremely capable human.

Quote source:
Plataforma SINC (2009, July 6). Scientists Develop Echolocation In Humans To Aid The Blind. ScienceDaily. Retrieved October 19, 2010, from http://www.sciencedaily.com/releases/2009/06/090630075445.htm

The Latest Echolocation Beacon Preference

noreply@blogger.com (Tim Johnson) — Wed, 11 Aug 2010 14:22:00 +0000

Image by bschmove via Flickr

Realizing that learning echo location when it is not an everyday necessity can be a long and arduous process, I’d like to apologize for not having posted here for a while. I’m am still striving to understand this phenomenon and I’m currently working to refine my beacon.

The Problem with Echolocating using the Mouth Click
I’m finding that making a clicking noise with my mouth presents several issues that I would like to avoid. I’m attempting to adjust my beacon method to something a bit more amenable to echolocation and modern social situations. Below is a list of downfalls I’ve identified about the mouth click:

It creates a sound source that is too close to my ears, making it harder to hear the echo over the source.
Less socially acceptable – not that that will stop me, but in an effort to offer the best solution to the inquisitive general public, I’d prefer something a bit less socially intrusive.
It denies you the use of your mouth for things like eating on-the-go, swallowing, talking, etc.
The time in between clicks is dead space and does not provide any data. In order to increase the resolution the clicks must get closer together.
Having the mouth open for long periods can cause dryness and discomfort.
Not a preferable method in quiet places, like the library.

My Latest Echolocation Beacon Preference
What I’ve been using recently has proven to be very effective. I would even say more effective than the blade pop or any other click I have tried. It is also non-intrusive to my environment – meaning it does not startle others and is acceptable to use in a quiet setting. The one negative observation I would make about this technique is that it is much better for sensing objects up close (up to 5-7 feet away) rather than far away. Objects that are farther than 5-7 feet away will most likely be difficult to pick up with this technique.

Place the thumb and forefingers together in traditional “sock puppet” position.
Slowly rub the thumb in circles on the fingers to create a high pitched rubbing sound.
To isolate the source from your ears turn your hand away from you so that the thumb and forefingers are on the opposite side of your hand. Your hand will act as a barrier and will direct the sound away from you and toward your target. Remember, you want to hear the echo just as well, if not better than the source.

As far as I can tell this method has a lot of advantages over the "blade popping" and other methods of clicking. (See the properties of a good click signal)

I guess another sticking point for this technique could be if your hands are not dry enough to create a sound when you rub your fingers together.

Anyhow, give this a try and let me know what you think about it.

Exercises for Improving Eyesight Naturally

noreply@blogger.com (Tim Johnson) — Sun, 11 Oct 2009 12:46:00 +0000

In ancient China, Shaolin monks developed a fighting style based on the physical characteristics and iconic elements of the personality of the Tiger. They called this Tiger style Kung-Fu. Since a Tiger has very keen eyesight, the monks developed methods of exercising their eyes to improve thier eyesight. These would have been exercises that they trained and developed from a very young age. They would have been performed by eveyone training in the Tiger style regardless of whether they had so-called "20/20 vision". No matter how good you are at something, you can aways become better with more training.

In today's age, we look at computer screens and through glass far too much. I have been recently practicing the following exercises and have noticed an improvement in my eyesight over just the past couple months.

One exercise was to count the leaves on a far away tree. With meditative patience they would focus in and count hundreds of leaves at a time. (This is a good one to practice in the fall since the leaves are changing colors and you may be staring at leaves quite a bit anyway.) Start up close with some leaves that are easy to make out and count 50 of them. With patience, slowly pick trees that are farther away from you and then slowly increase the number of leaves you count. Work your way up to 200 which will give you a good amount of time with your eyes focused at a distance. Do this once daily.

Another exercise is to focus on an object very close to your face. I usually choose my hand. Get it as close to your eyes as you can while retaining a good focus on it. Look at it for about 2-3 seconds after you've fully adjusted your focus on it, and then pick another object that is more than 20 feet away. I generally pick a leaf on a tree or something else that has some fine detail that will allow me to really focus on finer and finer detail. If you pick a flatt wall or something that doesn't have much texture or detail it will be hard to focus on. Again, look at the object for 2-3 seconds after you have achieved a good focus. Go back and forth between these two objects about 20 times and do this exercise daily.

The Mysterious Snapping Friend

noreply@blogger.com (Tim Johnson) — Wed, 11 Feb 2009 02:50:00 +0000

Image by Tojosan via Flickr

I just found out that one of my friends has been using echolocation her whole life. She assumed everybody could do it. She uses finger snapping.
It is actually fairly clean and I can navigate without bumping into too much stuff and with some speed.

This friend of yours does sound quite remarkable. I'd love to get a guest post from her on how she's been using it, why she started using it originally, and where she thinks it benefits her the most.

I tried snapping today and made a couple observations about it. First, it does seem to be pretty useful, it also gives you the ability to move your hand position around so that it is in front of your body or off to the side which blocks the sound from the opposite side of your body giving you resolution of whichever direction you choose as opposed to having to click with your tongue.

Another thing you can do is put your snapping hand out in front of your face and put your other hand between you and your snapping hand so that the initial sound is blocked from your ears and you only get the reverberations from the surroundings. This tends to bring out a little more clarity.

Not to mention that it is much more natural and socially acceptable than tongue clicking.

I crashed into my car the other day.

noreply@blogger.com (Tim Johnson) — Thu, 05 Feb 2009 11:11:00 +0000

Image via Wikipedia

Parking lots, I have found, are among the best places to practice echolocation for a few reasons: the layout is always different (cars parked in different spots), there are generally not a lot of other distracting objects around, and cars are relatively easy to pick up. As I mentioned in a previous post, cars (or metal objects, I guess) do have a very distinct sound to them. It's got to do with the resonance of the metallic body. I will have to look into that further.

But yes, if you're going to practice echolocation, get used to crashing into things. Perhaps I should have said that before.. I crashed into my car the other day, but I guess it's good that is was my car.

I'm finding that depth perception is different when I use the "Blade Pop" (see here) compared to the "Giddyup". It seems that objects sound closer than they actually are when I use the Blade Pop. I've walked up to a wall thinking that I was about 6 inches away when I was actually a few feet away. I guess this is a good thing because I think it means that there will be better resolution. IE.: If I'm getting a lot of response from something that is 3 feet away (maybe the same response I would get at 6 inches with another click) then I can anticipate obstacles better.

Also, this would imply that objects that are very close would be very obvious. This seems not to be the case quite yet, at least for me. It seems that there is a big difference when an obstacle is approaching 3 feet, but that there is not a lot of difference within those last 3 feet. I guess it just takes practice.

I just got up and did a quick test and I'm starting to think that maybe a click can be too loud to sense objects that are close up. I walked up to a wall using the blade pop, but then softened it to a barely audible sound, not even a click, and found that it was much easier to judge the very close wall with much greater accuracy. Probably to within an inch instead of feet. I'll have to explore this some more.

As always, feel free to share your input.

My Inspiration, Ben Underwood Dies at age 16

noreply@blogger.com (Tim Johnson) — Wed, 28 Jan 2009 11:56:00 +0000

Image by ZacharyTirrell via FlickrBen Underwood died at age 16, buried on Jan 26th, what would have been his 17th birthday. Ben was the initial inspiration for this blog and opened my eyes, so to speak, to a whole new way of realizing the senses.

As a small child Ben was blinded by Retinoblastoma, a cancer in the eyes. But his total lack of vision did not prevent him from doing anything he enjoyed. He still had no fears of taking up biking, rollerblading, basketball, and he lived his life as any other kid would, and did not allow himself to by "handicapped" by his situation. He learned as a child that he could hear reflections of sounds that bounced off of surrounding objects. He devised a certain "click" that he could make to interpret the objects around him. He was full of ambition and made it his life's work to perfect these techniques. Many blind people have begun to use echolocation, but Ben's talent was remarkable and he was the only person (as far as I know) who could distinguish the difference between objects as small as a stapler and a coffee mug on the table.

As I said, Ben Underwood inspired this blog and I will continue it, not only as a means to capture my meandering experience, but also as a thank you and tribute to him.

Thank you for your inspiration Ben, and your contributions to mankind. They will live on forever.

If you would like to leave a message or give a donation to Ben's family, you can do so at his website: http://www.benunderwood.com

I found my car in the parking lot using Echolocation!

noreply@blogger.com (Tim Johnson) — Fri, 23 Jan 2009 02:32:00 +0000

Today I found my car in the parking lot using echolocation!

I was coming out of the gym this evening, and there was about 60 feet to walk to my car. I took a look around at the pattern of cars so I knew how many there were between me and my car, and I knew what to look for. I also had a straight shot between myself and the car, but I closed my eyes and committed to finding it. I began to click using the "blade pop" (see Description) I turned my head from side to side, because I'm finding that the blade pop is not very good at revealing objects to the sides of the head - the "giddyup" is much better at this. I made out the several cars before mine and I knew there was an empty spot before my car. I located the empty spot and anticipated my car. I heard it right when I expected it, passed to the driver's side and stopped when I found the space between the driver's side of the car and the large snow bank. I opened my eyes, and voila!

Maybe next time I'll try going for the door handle...

How to Tune your Senses for Echolocation - Exercise #2

noreply@blogger.com (Tim Johnson) — Wed, 31 Dec 2008 11:25:00 +0000

<<--Back to Exercise #1

Sensitization Exercise #2: Listening to your Computer Monitor

This exercise will actually focus on hearing and interpreting the location of objects with your eyes closed. This is the basis for all echolocation and the principles from this lesson can be applied from here on out as you hone your skills.

Start by making a "ssshhh" noise with your mouth. You can also use "aaahhh" or many other steady tones.
Bring your face to about 12 inches from your computer monitor and listen to the sound you are making.
Now turn your head slowly to one side and listen as the sound changes. The sound will change due to the changing angle that it is hitting the monitor at, and once you have turned your head away from the monitor, it will change due to the distance of the objects that it is being reflected off of.

This exercise assumes that you have a fairly flat computer monitor that is directly in front of you and directly facing you, and that there are objects at significantly further distances (at least 18 inches) away from your face, on either side of it. Any flat object will work for this exercise. In the next exercise I will talk about using a flat piece of cardboard or plastic which would work just as well in the above exercise.

How to Tune your Senses for Echolocation - Exercise #1

noreply@blogger.com (Tim Johnson) — Wed, 31 Dec 2008 10:40:00 +0000

Image via WikipediaIf I haven't already said this, echolocation is not an ability that you're born with; something you either have or don't have, it is a skill that can be learned. Any hearing person can learn it if they are willing.

Your hearing senses will need to be sensitized in order to start tuning into hearing the different subtleties related to echolocation. These include phase shift, reverb, stereo effects, equalization, panning and more. These are all subtleties that musicians train themselves to be aware of, and you can do the same with the intention of using them to improve your echolocation skills.

Sensitization Exercise #1: Listening intently to music

If you listen to a lot of music, this is a good way to begin sensitizing, however, start listening more intently. Try to pick out every different instrument in a particular song. Begin noticing subtleties such as:

Which speaker is each instrument coming from? Or is it coming from both? This is called "panning", and often times songs will "pan" one guitar further to the left speaker and another guitar further to the right. This is done to give the effect that the guitars are in two different places on a stage. Once you've started to pick up on this effect, you should be able to point directly to where each instrument appears to be coming from, which should be somewhere in between the two speakers depending on how much it is panned one way or the other.
Determine how "far away" each instrument (including vocals) appears. This is basically accomplished by the recording company by adding more or less echo to the signal. If a longer echo (or reverb) is added to an instrument it will give it the effect of being in a large room and possibly far away. If a short echo (or delay) is added, it will give the effect of having very nearby walls and will be closer and more intimate. Generally vocal tracks have more delay added so that the singer seems closer and more pronounced to the listener.
Compare songs. Listen to how different songs compare to each other and how different recording companies like to mix songs.

Doing all of the above will help you to get started in sensitizing your ears to echolocation. This first exercise is something you can do on your own, but exercise #2, you will probably need a partner for.

Go on to Exercise #2 -->>

Echolocation Using Clicking Devices

noreply@blogger.com (Tim Johnson) — Fri, 19 Dec 2008 11:50:00 +0000

Image via WikipediaHandheld clickers may be used for echolocation, and I have had minimal experience with this, but I will dispel all I have learned so far. You can use a Snapple-type cap, or a pet training clicker. First thing's first, you must get used to the sound of the clicker. Play with it as much as you can, every day. Eventually you will be able to recognize it easily and at this point you will have learned many of the subtleties of the sound. Clickers should be sounded around the waste level or above the head, don't click them near the ears since this will defeat the purpose. The goal, as always with echolocation, is to create a triangle between the source, object and receiver. So in this case: clicker, wall, and ear.

I find it is also helpful to create a barrier directly between the clicking source and your ear. This could be your other hand (as if saying "Stop") a notebook, or even a bag you're carrying. This will prevent the signal from going directly to your ear and will isolate the reverberating signal (which is the important part)

When using a clicker, pause for about a second between the press and the release of the button. This will give the reverberations time to subside and will avoid confusion for your subconcious.

An interesting observation on clicking... or not clicking.

noreply@blogger.com (Tim Johnson) — Wed, 26 Nov 2008 11:23:00 +0000

Image by vinduhl via FlickrI was echolocating through the hallway at work the other day, and I noticed a lot of high frequency noise which I think has been there all along, but I hadn't really paid attention to it. I think it was either coming from the deformation of the carpet fibers under my feet, or the stretching of the fabric in my shoes because it was synchronized with my gait. It wasn't necessarily just the sound of footsteps, because it seemed like it was always present, and just increased in volume at every step.

After listening to this sound for a while I realized that I was actually using it quite effectively to echolocate. Possibly more effectively than clicking. And I can see where the myth of "pressure on the face" comes from. Since this sound was more omnipresent than the sporatic clicking you get a much better transition between the "presence" of different objects.

This makes me wonder, if some white noise were to be emitted at, say, the belt buckle level (somewhere away from the ears, but a source that travels with you) if that would be of great benefit for echolocation. Maybe clicking is not the way to go?

Anyone out there ever notice this phenomenon? Let me know what you think.

Getting used to a new echolocation click

noreply@blogger.com (Tim Johnson) — Sat, 08 Nov 2008 21:04:00 +0000

Image via WikipediaI'm working on getting used to the "Blade Pop" click. (See article on "Analysis of Different Clicks") I find it is a good idea to perform the click as you walk around. When you're clicking just listen to the sound of the click. If you are seeing, then feel free to keep your eyes open, if not then observe in the best possible way, the nearest object and listen to the sound and how the sound changes as you walk around and move from object to object or from room to room.

After doing this for a while you'll start to notice the slight differences in the sound, and you'll be able to make little tweaks in order to improve it. (See article: "Properties of a good Click") Even if you don't think you're noticing, you may very well be subconsciously learning, as a great deal of echolocation is achieved by subconscious recognition. You can change the frequency by changing the shape of your mouth, and if you continually make the sound you will just get accustomed to it, and gradually it will become easier to use it for echolocation.

Waveform analysis of Tongue Clicks for use with Echolocation

noreply@blogger.com (Tim Johnson) — Tue, 04 Nov 2008 12:07:00 +0000

For this post, I have analyzed three of the more popular methods of clicking. Using a studio recording microphone (AKG Perception 200) I recorded myself clicking to the best of my ability. The three clicks in question here are:

The "Cluck": Made by lightly pressing the tip of the tongue against the roof of the mouth and then breaking the vacuum and smacking your tongue against the floor of your mouth.

The "Giddyup": This one is made by breaking the vacuum and drawing air in between the sides of the tongue and the molars, and is commonly used to communicate with horses. This signal, by nature, is produced at the sides of the mouth, and therefore is emitted away from the sides of the head. This is interesting in that we can send the signal to either one side or the other, but it is more difficult to send the signal directly to the front with this method.

The "Blade Pop": This one is the most difficult for me, but sounds like the one used by many proficient echolocators. This requires that you suck the blade of your tongue (the big meaty part in the middle) up against the roof of your mouth until you've got a good amount of surface-to-surface contact, and then break the vacuum by pulling your tongue away. This one requires significantly more vacuum than the previous two. When executed correctly, it sounds distinctly like a bottle cap being depressed or released.

The frequency of all three clicks described above can be adjusted slightly by the shape of the mouth. Generally a wide mouth or smile will generate a higher primary frequency, as well as make you appear happy :)

Signal Analysis

Below, I've uploaded the waveform generated by each of these clicks, as well as a spectrum analysis. The waveform shows the amplitude of the sound over a certain time period (as indicated), and the spectrum analysis is a plot that lines up with the waveform and shows the distribution of frequencies that occur within the sound signal. Brighter colors meaning higher concentration of waves in that region. Higher frequencies are at the top and lower frequencies at the bottom of the spectrum analysis.

The Cluck (200ms):

The cluck waveform is neat because you can distinctly see two spikes. The first small spike is the tip of the tongue separating from the roof of the mouth, and the second spike is the tongue smacking against the bottom of the mouth. Although the latter is significantly more prominent than the former these two sounds are within 10-15 ms of one another and have the potential to cause interference to the listener. This signal could introduce ambiguity.

The spectrum analysis shows that most frequencies coming from the cluck signal are quite low. The higher the frequency, the more energy it has and it also allows for better recognition and better resolution. (See Properties of a Good Echolocation Click) A broad distribution of frequencies would theoretically give you a reliable signal since some frequencies will be absorbed by objects and others will be reflected depending on the resonant frequency of the material or object.

The spec to the right of the actual signal is not an echo, but actually a drop of saliva swishing around in my mouth as an artifact of the signal creation.

This is the signal I started with, but have not had a lot of luck using it effectively. I think this is primarily because of the concentrated low frequency and "double pop".

The Blade Pop (100ms):

Notice the sound envelope as compared to the "Giddyup" below. The "attack" (time it take for the signal to get from zero to peak amplitude) is much less for this signal. Approx. 7ms for the Giddyup, as opposed to about 1ms for the Blade Pop. This gives the signal more of a distinct "pop" which will actually impact objects better and thus be reflected better. Think of it has a "harder" signal. A superball bounces better than a sponge. In other words, the object can be absorbative making it difficult to bounce a signal off of, but the signal can also be "squishy", making it easier for the object to dampen the impact as opposed to reflecting it.

Notice that there is fairly good distribution of the signal although there is a blank spot, and there could be more in the high end which would make for a better signal. If you look at the spot about 70% through the spectrogram, you'll see a faint echo of the higher frequencies. This is approximately 70ms from the generated signal and probably corresponds to the shape of the signal bounce pattern in the room. A 70ms delay would mean approximately 70 feet of signal travel, so this signal is more like an echo after the signal has bounced around the room a while as opposed to the instant ricochet off of the nearest wall.

This being the sound that I am struggling with, it may be that, with practice, I could distribute the signal over a wider range of frequencies and become more accustomed to its sound.

The Giddyup (300ms):

The signal itself has a 7ms attack as discussed above, and the signal itself is about 25ms as opposed to 12ms for the Blade Pop.

Good distribution of the signal, a little ricochet at about 70ms on the higher frequencies. As mentioned above, this one is directed away from the sides of the face, which may or may not be a good thing. It's nice that it is more inline with the ears, but then you have to turn your head slightly in order to notice objects directly in front of you.

This is the signal that currently gives me the most accuracy. I am accurate within 1/2 inch or so of flat walls whereas the Blade Pop only gives me accuracy down to 6 inches or a foot. I will need to play with that signal a bit more and report back, because I do like the distiction of it. It is much more "poppy" than the Giddyup.

I will need a more sound proof room and more controlled environment in order to directly observe the reflexive properties of certain objects with these clicks. It's a good thing the human brain is faster, smarter and more acute than any computer, otherwise we'd still need our eyeballs to see things.

Properties of a good Echolocation Click Signal

noreply@blogger.com (Tim Johnson) — Tue, 04 Nov 2008 11:45:00 +0000

If I try out different clicks and postulate which click I think works best that would be extremely subjective and I’m sure that different clicks work better for different practitioners. However, there are many fundamental qualities of a click signal that make the signal better suited for echolocation:

Signal Frequency. The frequency of a signal governs the resolution, in that a shorter wavelength (higher frequency) will give you more definition as to what it has bounced off of. Low frequency waves, since they have a longer wavelength are not as distinct. It has been said that the region of 3kHz is a good place to be for echolocating.

It is my hypothesis that a broad distribution of frequencies would be desirable (above a certain value) so that if some frequencies are absorbed by an object, others will be reflected by it.

Signal volume. The sound must be loud enough to stand out over ambient noise. 40 dB is about the level of quiet speech from a few feet away.

Clarity. This is probably one of the most, if not the most important property of the sound. It is critical that after the sound is made, there are no artifacts of the signal source still emitting sound. In other words, the sound must stop abruptly so that the reverberations can be clearly heard. If the sound were to taper off at all, this small amount of sound would easily cover up the reverberations, or at least create a confusing blend of signals.

Directional. If the signal is omni-directional, IE, if it is the same volume in all directions from the source, it will be difficult to know the direction from which it is being reflected, and thus where the object is that is doing the reflecting. Think of it like a flashlight. You can point a flashlight at one object and see what it is. Whereas, if you switch on a light bulb you are able to see everything in the room and there is more information to take in. When echolocating, we want to eliminate as much excess information as possible.

Passive Echolocation Signals

noreply@blogger.com (Tim Johnson) — Thu, 30 Oct 2008 16:51:00 +0000

Passive signaling during echolocation involves listening to the ambient noises in the room and interpreting them. It has it's pros, such as not being intrusive or noticeable, but it is not the best method for accurate echolocation. These sounds can be:

People talking
A running fan
Footsteps
Clothes rubbing against each other
Hands rubbing together
Breathing
or other omni-directional sound sources.

One of the downfalls of these sounds is the fact that their source is undefined, and therefore any sound that is reflected to the listener has the potential to be bouncing from any direction and can not easily be used to identify the shape of objects.

These sounds can however be used to make broad observations such as the size of a room or proximity to a flat wall. Other estimations may be possible depending on the actual content, level and clarity of the sound and any other distracting sounds that also exist, noticeable or unnoticeable.

Echolocation in Terms of "Reverb"

noreply@blogger.com (Tim Johnson) — Wed, 29 Oct 2008 01:20:00 +0000

Image by Northeast Indiana via FlickrLet's look for a second, at echolocation as it would be viewed by a musician. Every different room, every environment, indoor, outdoor or otherwise has it's own acoustical properties. These would be known to musicians as that room's reverberant properties, or it's "reverb". Certain rooms are said to have a certain type of reverb. Rooms with hard flat parallel walls generally have what is considered to be "a lot" of reverb, where rooms with softer (more absorbant) walls that are oddly mishapen are said to have less reverb, meaning that the sound is not as likely to bounce around as much. A highly reverberant room is labelled such because the sound waves are likely to bounce off of the walls, sometimes several times before making their way to the listener. This gives the effect that one short tone is stretched out over a longer period of time. Essentially, the reverb is made up of many very quick echoes from nearby structures.

You have undoubtedly experienced and are familiar with certain reverb characteristics. For example, if you are in a quiet environment and you close your eyes and snap your fingers, you will immediately be able to tell if you are in a bathroom, car or auditorium. If you thought about it a little longer you could probably guess if the floor was carpeted and what the walls were made of.

Since the exact shape of any room give it it's reverb, this is essentially the same thing as echolocation. Save for one small detail, movement of the source and reciever (sound source and your ears). A room can have reverberant qualities and you may be able to make generic assumptions about the make-up of the room by listening to a sound, but without moving the source and reciever you would be hard pressed to tell the shape of the room or identify any objects in it.

Once we move, we gain another dimension of information. The "echoes" which are making up the reverb we are listening to as we click to echolocate, are changing direction as we move our head. It is not one click that gives us the information we require, but rather the difference between one click and the next which tells us how objects are moving with respect to us, and therefore how we are moving with respect to these objects.

If you have watched people echolocate, you will notice that they move their heads from side to side, tilt their ears and walk around objects in order to distinguish what they are. They are taking the information differential between clicks and piecing it together like pieces of a puzzle. It may take several clicks before someone is comfortable in their surroundings or can identify an object. I would think it to be nearly impossible to gather much environmental information with just one click no matter how good versed you are in echolocation.

The Basics of Echolocation - How to Know What to Listen For?

noreply@blogger.com (Tim Johnson) — Tue, 14 Oct 2008 10:18:00 +0000

Image via WikipediaIf you've never tried to echolocate before and don't really know what it is, then read this article, it will give you an idea of what to listen for.

One of the first times I noticed the effects of echolocation, I was sitting at my desk at work, and listening to the radio. The speakers were biased to one side of my head, and I raised a hand up on the opposite side of my head - maybe one foot away - and found that the sound reflected off my hand and into the ear that was getting less music. Try this, and now move your hand around a listen for the sound reflections. If it's not obvious enough with just your hand, try a folder or binder (something larger, flatter, and more rigid will be a better reflector). The image above illustrates why flatter surfaces make better reflectors. Sound reflects off of objects similar to the way light does.

Now try twisting your hand or binder back and forth, but keeping it in one place so that you're reflecting the sound away from your ear, and then directly at your ear, and then away in the other direction. It should appear as if the sound source is passing by, while really, it is just the shape of the reflecting object creating different effects.

The effects you will hear from this exercise are quite a bit more pronounced than the effects you will see when you start using clicking to echolocate, but this should give you a good idea of what kind of effects can be observed when sound reflects directly off of a small object.

Echolocating Through a Doorway

noreply@blogger.com (Tim Johnson) — Fri, 03 Oct 2008 15:10:00 +0000

Image via Wikipedia

To get a feel for echolocating you can try this quick exercise in an inside doorway.

Stand 3-4 feet in front of a doorway. If possible the door should be positioned in a flat wall and it should be fairly clear of obstructions on either side. Make sure there are not too many distracting noises surrounding you, it’s certainly easier if it’s a very quiet environment. Oh yeah, it’s also important that the doorway does not have a threshold, this will be a dead give-away later on.

Close your eyes and listen. Take notice of any ambient noise around you. Notice how these ambient noises change as you turn your head. Address the doorway and make the clicking noise of your choosing. Turn your head back and forth to click in the direction of both sides of the doorway. Step forward toward the doorway and observe the changes.

Finding the door. Step all the way through the door and notice the changes in sounds from one room to the next. Try to hear when you are exactly inside the door jam. Try to hear if you are closer to one side than the other, remember to keep turning your head. Focus on one ear at a time, what are the differences? If you think you’ve made it, open your eyes or grab onto the door jam to see how you’ve done. If you’d like you could try turning 90 degrees and approaching one of the sides of the door jam and see how close you can get your nose to it without touching it. While clicking, make your estimate before you verify your success.

Echolocation Practice - Walking a Predetermined Path

noreply@blogger.com (Tim Johnson) — Fri, 03 Oct 2008 09:38:00 +0000

I was visiting a friend down the road last night, and on my way home it was fairly dark and there were not a lot of people roaming around my little suburban-type town, so I was able to get in some good echolocation practice. My trip was about 1/2 mile and it is a fairly straight shot on a somewhat even sidewalk. I am still very much a beginner at this so if you already echolocate, this will probably not be news to you, I can only offer my observations of myself as I'm learning.

This was my method that seemed to be fairly fruitful:

Sighting your target. With your eyes open, look ahead, down the path that you are to travel. I find that somewhere between 30 and 60 feet is a good starting distance. Pick a distance that is long enough so that you will not be able to count your footsteps, but short enough that you will not get discouraged or lose track. Pick a landmark at the end of the path; a telephone pole or bush that you can end at. Familiarize yourself with the lay of the land so that you will have a starting point and some familiarity. Notice changes in terrain, bushes, parked cars, telephone poles, fire hydrants, etc. If you are blind then you'll most likely be attempting to navigate a path that you have previously used a cane for, and are familiar with the obstacles that you must avoid.

Setting your course. Once you know approximately where you're trying to get and what obstacles you need to avoid, it's time to set you course. Which side of the tree will you walk on? Will the fire hydrant by to your left or your right? Will you need to adjust your direction to navigate around obstacles? By doing this you will be able to break up your echolocation journey into smaller segments. (IE, after the firehydrant, vear right to avoid the overhanging bush.

Closing your eyes. Close your eyes. If you are blind this mean stowing your cane. You will probably be tempted to peek... it is natural, but don't, it kinda defeats the purpose..

Echolocating. Now to begin the echolocation journey. The first few steps you will be expecting. The immediate terrain and obstacles will be in your short term memory and you will easily navigate them without clicking. But click anyway so that you can hear and get familiar with the echoes. As you approach your first large object, maybe a car, tree or telephone pole, be aware that it is there. Listen for it and concentrate on the echoes. Obviously, the point here is not to touch anything that would give away the path, but if you are nervous about smacking your face into anything you can keep your hands up. I would suggest keeping them low and out of the path of your clicks, however.
Objects that are nearer to your starting point will be easier to pinpoint. Click in the direction that you are expecting to find an object. Once you have reached a landmark, acknowledge it, try to judge it's distance, and then visualize your path with relation to it. What is the next landmark? The car on the left? Focus on the path and continue down it with a strong concentration and expectation of hearing the reverberation off the car. Once you get to it, acknowledge it. Notice the differences between the car and the telephone pole. The telephone pole, since it is round will sound the same from any direction. The car will change its reflective properties as your angle to it changes. I find that cars and metallic objects also reflect higher frequencies due to their less absorbent characteristics.
Reaching your goal. Once you have navigated yourself through you predetermined path, you should be at your end landmark. Be sure to stop when you have gotten to the landmark and acknowledge it. If possible, walk around the object still echolocating and clicking towards it. Remember not to touch it! Are you sure this is the correct object? Or is that thing you think is a telephone pole actually a bush? How far away from it are you?

Open your eyes. Take out your cane. Confirm the object that you've approached. Is there even anything there? How close did you come? Keep clicking for a little bit to understand what you are hearing. Where you hearing another echo from a nearby tree that threw you off? Did you judge the distance accurately?

Now wasn't that fun? As I'm typing it, it got a bit more involved, and I will certainly be typing up more exercises that might be easier, and as I progress, getting a little harder. Good luck with this one and don't get discouraged if you're not getting it. Just try objects that are a little closer or larger.

The Profundity of Echolocation and the Human Race

noreply@blogger.com (Tim Johnson) — Thu, 02 Oct 2008 16:39:00 +0000

Image via WikipediaSo why am I learning (trying to learn) echolocation? Not because I expect to go blind anytime soon, or because I want to be able to navigate in the dark, or show off by walking around with my eyes closed. Really, the reason I want to learn it is because it's an ability that humans are capable of, and in an effort to get the absolute most out of life I think it's important to know yourself, understand your limits, and to test them. My physical limits, (how fast I can run, how high I can jump, how hard I can punch, etc.) I have worked with for my whole life and have always tried to improve them.

Echolocation is a physical ability that we posses and has been proven by many blind people. It's primary function is currently with the blind population, and while the blind are said to have more acute hearing, it has been tested (even amongst the best echolocators) to be no "better" than the average person. They have simply been given the opportunity to put more focus on it and thus have become more in tune with its subtleties.

Thousands of years of human development are to be attributed to the fact that we use tools, brains, and all of the abilities at our disposal. Echolocation is an ability that has gone unacknowledged for many thousands of these years. Certainly there have been people to use it, most likely blind, (the case of James Holman stands out as notable amongst many blind people who claimed to be able to see objects via "pressure" on their face, or "facial pressure") but it has not been brought to the attention of the mainstream public until very recently.

Imagine that the human race had never realized that it was possible to hurtle one's body through the air, curl it up into a ball, flip around and land on one's feet. The first time someone successfully landed a front tuck was a revolutionary turning point in one small area of human development. This is an incredible ability that is not necessarily feasible for everyone, but the human race has worked hard to develop it into a sport and a form of entertainment. People practice it because it is challenging and enjoyable. Take, for example, even our little fingers. What if we had not discovered them, or for some reason not assumed that they were for a similar purpose as the remaining 8 fingers? If we never used them we would be missing out on a major functionality of our bodies.

This is much like echolocation. If your parents had told you that you could hear the sound reflected off of objects, and told you "Listen to where the tree is" just like they told you "Look at what color the ball is" then you probably would have grown up with at least an acknowledgment of the existence of this ability. It is human nature for people to explore their own abilities and therefore you probably would have practiced or at least noticed this sense in your development. Now, what if people had been developing this ability for the past 10,000 years, just like the abilities of speech, walking or running. Imagine where we would be. The world of darkness and blindness would be so much less foreign to us and there would be many opportunities and abilities which inherently implement echolocation that would easily become apparent should we refine this ability.

As Eric Schwitzgebel stated in his blog Echolocation and Knowledge:

...most of us, even if not wrong in quite that way, are strikingly ignorant about this aspect of our stream of experience.

We have so much room for development in the area of echolocation, and so much to learn. I'm glad that we have not reached the final plateau in learning about ourselves (although I know that would be an impossibility), and I'm curious as to when people will begin to effectively use their skin, hair and eyes to listen to pick up audio vibrations and be able to interpret sounds, music and speech. ... Right? Who's up for that?

Working on the best Click for Echolocating

noreply@blogger.com (Tim Johnson) — Wed, 01 Oct 2008 08:58:00 +0000

The sound emitted during echolocation is critical since it is the direct properties of the reverberations of that sound that you'll be analyzing. This means:

It's got to be a sound you are familiar with. You know the sound of you front door and you know the sound of a soda or beer can being cracked open. Sounds like these are powerful in that they instinctively trigger thoughts and emotions prior to you actively conceptualizing their source. The sound you use for echolocating should be similar to this so that you are familiar enough with it to recognize the very subtle variations that are necessary for echolocation.

It's got to be consistent. Whatever it is try not to change it up to often unless you experimenting. One sound may return different reverberant characteristics than another in the same environment.

You've got to be able to hear it. It doesn't make a lot of sense to make a sound that will be difficult to hear, which implies that the sound wave must have enough energy to return to your ear, and still be recognizable. Higher frequencies have a higher energy than lower frequencies and therefore will return better. They will also give you better resolution since the wavlength is shorter.

Here are a few of the different tones I've been experimenting with:

Car engine. This is used when driving with the passenger's side window open and echolocating passing objects. Read echolocating while driving in the car, for more, but you've got a great tone for a lot of reasons:
- There are many different frequencies present.
- It is consistent.
- It is loud. I have been able to echolocate and determine the shape and material of objects up to about 50 feet away from the car.
- It is not directly heard inside the car. Meaning most of the sound is outside the car and can be reflected inward making the reflected sound the dominant one as opposed to the source.
Footsteps. These are okay to use since they are generally distinct and high frequency, but I find that they are very inconsistent depending on the terrain and what kind of shoes you are wearing.
Scuffing of pant legs. Fairly consistent, but usually just not loud enough.
"Cluk" - The sound of the tongue smacking the bottom of the mouth as if to make a "clop" or "pop" sound. As far as I can tell this is what most practicing blind people do including Ben Underwood. It gives a nice quick defined tone that is fairly high pitched. And since the mouth is closer to the ears than say, the feet, the reverb characteristics, I would think, are more accurate.
"Kik" - This is a sound made on the sides of the tongue as if you were guiding a horse. It is made by sealing the tongue against the roof of the mouth and creating a negative pressure inside your mouth and then releasing your tongue's seal. It will result in a "kik". I've taken a liking to this one for a few reasons:
- It's even higher pitched than the "cluk".
- It's easier for me to make, therefore I can make it louder.
- It emanates from the sides of the mouth rather than the front thus reflecting more of the tone directly back into the ears.

So I'm going to keep using the "Kik" method and we'll see how that goes. Another thing I wanted to try was snapping with my fingers somewhere under my chin. I will try this and report back if it is any good. The reason I say under the chin, is so that the sound source is close to my ears, but the direct signal is somewhat blocked by the underside of my face leaving me with a better perception of the sound as reflected back.