"We hear in stereo 3-D." This is not true unless we move our heads. We hear in one dimension, left-to-right.
"We hear better than we see." This is an apples-to-monkeys comparison.
Another is the phase difference of the sounds in both ears. Phase difference comes from the fact that sound arriving at one ear had a longer way to travel than sound arriving at the other ear. tells a more complete story of direction than loudness and is very precise.
Thirdly, there is frequency response. Both our head and our ears absorb different frequencies at different angles. Also, there are some reflections from our shoulders and chest.
Taken all that together, normal people can detect the origin of sound sources to about one degree of precision.
But, there is more. Close your eyes and have another person talk while turning his head in different directions. You can clearly detect the direction he is talking to. At the same time, you can roughly sense the size and type of the room you are in. Also, you can do this while being in really noisy environments (say, a car in traffic with the radio playing and the kids in the back).
Talking about seeing vs. hearing: The response time of the ear is about 10-50 ms. It usually takes 200-500 ms to make sense of something you see. The human ear has a frequency resolution of about one Hz (at <500 Hz), a dynamic range of about 120 dB and a frequency range of about 10 octaves. The eye can only detect a very small dynamic range in comparison, and about one octave of wavelengths. But most importantly, the eye can only detect averages of three distinct, fixed frequency ranges (red, green, blue; red and green overlap 90%). The ear has floating detection windows and uses an arbitrary amount of different windows at any one time. That is, the ear can detect any spectral distribution with great precision, while the eye only detects three distinct spectral windows.
So in a lot of ways, the ear is physically way more precise than the eye. Of course, signal processing makes all the difference and the amount of signal processing going on in our acoustical and visual brain centers is just staggering. There is nothing in the technological world that even comes close to that.
I think it’s pretty silly to argue that hearing can pick up more detailed information about the world than vision can: from vision, we can figure out shape, orientation, distance, texture, gloss, material, lighting, direction and speed of extremely tiny motion, etc., and we can do it for fine details of everything we look at, thereby constructing a tremendously detailed model of our environment without needing to directly touch every part of every thing. Anyway, both hearing and vision are extremely sophisticated. The two gather quite dramatically different kinds of information. Neither should be underestimated.
But all this is really not as important as the signal processing that makes sense of it. There are interesting connections between hearing and seeing. If you watch TV and someone at your side turns his head to you in order to speak, you will notice and shift your attention to him. You will think that you saw his head movement in the corner of your eye. But truth is, many people wearing hearing aids will not notice the same situation, for the simple reason that you actually did not see his head movement, you heard it.
There are many more examples where things like this happen. What you perceive is different from what your senses detect. All these intricate combinations of sensual information are the really interesting part.
Another fun thing about hearing: The human ear can detect very low sound pressure levels. Actually, it will detect a displacement of the eardrum of about the diameter of an air molecule. In a way, this is saying that the ear can detect the impact of individual air molecules on the ear drum (not really true, but in the ballpark). That is freaking amazing.
As an analogy to radio equipment we might say that human ears have automatic gain control which spans 120dB (or as audio comparison we can adjust the volume on that span) but the range which we can discern two sources (the instantaneous dynamic range) is about 30dB or less.
Also about the frequency resolution of the ear vs the eyes the bandwidth are on a completely different scale. Visible light spans about 380THz which means that the bandwidth of that signal is 19 250 000 000 times the bandwidth spanned by our ears. You cannot do just simple octave based comparison as the amount of information is not dependent on the amount of octaves but only on bandwidth. You are correct in the sense that the eye uses this information in quite limited fashion, however the actual processing is not on normal frequency domain but on spatial domain (eye is not just one sensor but craploads of them).
(eta: just posting the link seems kinda snarky -- this ties into your post, but i don't have anything else to add)
Put on some headphones and listen to this and tell me you cannot visualize it in 3-D:
http://www.youtube.com/watch?v=YuxaOO6PsAw
This is a binaural recording. More info on these here: http://en.wikipedia.org/wiki/Binaural_recording
You can hear in multiple dimensions because, as the original article mentions, there is some post-processing in your mind due to the time delay between sounds entering your left ear and sounds entering your right. Just because your ears are aligned on a single axis does not mean that you cannot perceive in multiple axes. No moving of your head is necessary to perceive in more than one dimension.
And I wonder, why else would we have such oddly shaped ears?
There's something funny going on with front-back perception. Normally it shouldn't be doable, but the external part of the ear is like a direction-dependent frequency filter. When the brain hears a familiar sound, but the spectrum is skewed just like this, it goes "aha, this comes from the front side". If the spectrum is skewed the other way, it goes "this comes from behind".
It's not 100% reliable, but it works some times.
There's a lot more to it than that, and it's not just something that occasionally works. The outer-ear notch filtering is also used in vertical localization.
While our localization abilities vary by axis, we do have them in all three directions due to the combination of several mechanisms, none of which are actually 'left-to-right'.
Sounds like he needs some real angels, those who measure the success of their investment in something bigger than dollars. How does one go about finding and pitching to them?
If he got the K-Sonar approved as a medical device, I think he'd be able to get paid from deep-pocketed insurance companies too.
Improving the range (and doing research on inner-ear microphone implants) could be done in later versions (if mainstream blind customers really are interested in playing tennis, which I am skeptical about). If v1 makes people more independent, that's a huge deal already!
I bet he could get pretty far just by reallocating his existing $200k/year budget to commercializing the technology, which has the potential to be embraced by a lot more people than the blind people he is introduced to (only 10% of whom even get good at echolocation-through-clicking).
It also doesn't sound as though he knows much about startup methodology or has the personality or desire to solve the bootstrapping problem. He's seems like a domain expert but not an entrepreneur.
I guess that means a lot of blind people will have fewer opportunities.
There is an easy(cheap, i'd say tens of dollars, see prices for ultrasound parking sensors) implementable "virtual cane" : the pair of laser (like in laser pointer) + receiver + small chip which would re-scale the sensor output to the hand from light speed scale (10m / 300000 m/s = 0.00003s ) to the tactile feedback scale - tenths of a second. The same can be done with ultrasound. The both can be even paired, for precision and cases of say low light (or sound) reflecting surfaces.
The main problem i think is that blind people have their hands full just trying to live the life, while non-blind don't care and or passionate enough to cross the threshold into doing something. The guy in the article is just a miraculous exception.
Even Steve Blank recognizes the model doesn't fit for medical devices.
If you look at the history of Kickstarter's most successful projects, they tend to resemble pre-sales more than "donations." There's usually a product delivered at X level of individual funding, and 90% of the funding comes in at X level.
This model is fantastic for launching new products that are ready to go upon receipt of funding. It's not as successful for raising money for R&D.
"Do you see blackness all the time?"
"No, I don't know what blackness is; I see the same as you see out of the bottom of your feet".
A blind person who has a sense of the size of a room, have they any idea that windows are transparent and have a view over a vast area of cityscape/fields/oceans/length of road/etc?
Standing on a hilltop or in a viewing tower, you can see people in the landscape, but too small to see their faces or identify them - still identifiable as people by shape and gait.
I often automatically turn to Google images for an idea of what something I'm unfamiliar with "is", having to revert to a dictionary and textual description would feel like a step backwards, and that's a very recent (last 5 years) development.
You could also ask if blind people are able to perceive vision in dreams. To which the answer, I believe, is that they simply cannot, due to the fact that their brains have no notion of a visual image.
Those who've never seen, or who were blinded very early, have auditory dreams. (They dream in sounds.) Those who were blinded after the age of around seven -- when the ability to form mental images necessary for dreaming develops -- are able to dream in pictures.
One can argue that 'seeing' goes beyond the perception of lights and colors. It's also about shape, so I guess a blind person can perfectly 'visualize' a rectangle, a cube, etc. And probably do geometry, or even 3D-object rotations.
Can anyone confirm this?
Although I do agree the dialog popping up at the beginning is annoying, it's only one click (or key) to dismiss it; I prefer that to having to click on several "next page" links.
If you look at my other post, I linked to a video of a kid who used echolocation. He could distinguish objects - he walked past two garbage cans in the street, and said "Is that a car? clicks his tongue several times No, it's a garbage can."
I'd like to get his opinion of this: http://www.seeingwithsound.com/
'You might think of it like being in a choir or an orchestra... The world is like a living symphony... This car is kind of like an instrument, except that, instead of making its own sound, it's reflecting sounds I'm making.'
Extraordinary.
The video is from when he was 14, he died from cancer at 16.
http://en.m.wikipedia.org/wiki/Daredevil_(Marvel_Comics)
Not an amazing contribution to the thread but relevant and hardly worthy of punishing with downvotes.
(Direct Link: http://www.youtube.com/watch?v=YBv79LKfMt4)
http://www.mensjournal.com/the-blind-man-who-taught-himself-...
I have once seen tests in some popular science tv show. They blindfolded a few people and let them walk in front of a door (or sth like that) to check if they'll stop before they reach it, and somehow they managed to do it. We can use echolocation by nature, we just don't develop this skill.
OTOH, eye implants are probably not that far off.
> Just the auditory cortex of a human brain is many times larger than the entire brain of a bat.
This really startled me. It seems plausible that we could do as well, with early training etc. Plus, I imagine that some of the higher-order processing of the occipital cortex would also be seconded.
Pain is part of the price of freedom. That's a truth that could use to be applied more widely.
Kudos to him. It's amazing how people have the ability to reprogram their bodies in order to break their handicap.
Reminds me of a story "Blind Teen Gamer Obliterates Foes" http://www.wired.com/gaming/gamingreviews/news/2005/07/68333
Appalling. Forcing people to be cripple because solving it might be "off-putting" or "abnormal" [1]. Blind people being able to do all the things the sighted can do (and more in some cases) is worth hearing a few clicks now and again.
[1] I say "solving" because Kish doesn't seem to be at a strict disadvantage. He has disadvantages and he has advantages in areas we don't (e.g. finding the way out of a car park, "seeing" around corners, etc.).
Still very cool.
