"you can hear 'silent' objects." human echolocatio

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bigugly

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Jun 27, 2004
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220
Location
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here's a good article from Discovery on how the brain processes the ambient and reflected sounds of our environment even if we are not aware of it.

http://dsc.discovery.com/news/2008/06/11/hearing-sound.html
 
> the brain processes the ambient and reflected sounds of our environment

Tiger toe on a twig. Where is the tiger? QUICK!!!

Our forefathers/mothers had this skill, estimating reflection patterns, or they became tiger lunch.

Conversely, my Corgi-dogs are fairly good at locating small prey by ear. They would be a lot better if they had to do it to eat.

When I was young, dropping screws under my desk, I was often pretty sure where it went before I got down there. I'm less good now, partly old ears, partly more carpeting and more clutter diffusion.

There is a story of someone getting a tour of an anechoic chamber. He says he stopped just inside the door and told his guide he sensed an object "this big" behind him. The guide pointed to a speaker baffle just about that size mounted over the door.

The size of drivers, horns, and baffles colors loudspeaker sound; while hi-fi guys try to confound this sense, guitar cabinets use it to good effect. You can't mistake the sound of two 12" cones in a 30" open baffle. One 8" in a closed box never sounds the same even if driven to the same level and nominal frequency response.
 
Corgi-dog digression:

Watch a dog that loves its owner next time the owner goes into the garage and leaves the door opened just a crack...

The dog usually cocks its head sideways. -It won't consciously tell you why, but of course the stereophonic angular location now converts from fully left-right to (at least partly) up-down. -Since the dog knows the approximate height of its owner, it will usually be able to get out of the way at precisely the moment before the door opens and smacks it on the muzzle...

-The parallels with B-format/Ambisonic pickup are fascinating. -Well, to me at least.

Sadly my old dog is now almost deaf. -He has a flat muzzle as a result...

..Looks a little odd on a cocker spaniel, -but I just tell people that he's chased one too many parked cars, and they seem to accept that more readily.

Keith
 
Actually, isn't it our ears that emit ultrasound vibrations that are then sensed for spatial recognition? IIRC, tinnitus is a dis-comboburlation of that physical characteristic?
Silence is NOT silent, unless you are deaf.
Mike
 
In the dark I can find the middle of the bowl with my stream from the sound alone...

JR

PS: Talking about hearing tiny sound I once had a traveling blood clot make it way into the very fine blood vessels in my inner ear. At night while I was laying in bed I could hear a whoosh with every heart beat as the blood pumped past the partial blockage.
 
> The dog ... will usually be able to get out of the way at precisely the moment before the door opens and smacks it on the muzzle...

> In the dark I can find the middle of the bowl with my stream from the sound alone...

Ears are very clever things.

The research described from that link is not even interesting, except in that this topic has been woefully neglected as a source of employment for grad students. Let them play with their carts a while, and I'm sure they will get into more subtle hearing tricks. Maybe put a camera centered on John's john and correllate dark accuracy against inner-ear clot location. A number of more data-profitable baby-step experiments come to mind.

> smacks it on the muzzle...

Brains are required. What you describe: Bonny can do it, Molly can't. Bonny is as smart as she wants to be. Molly is stereotypical "blonde" through and through.
 
[quote author="JohnRoberts"]In the dark I can find the middle of the bowl with my stream from the sound alone...

JR

PS: Talking about hearing tiny sound I once had a traveling blood clot make it way into the very fine blood vessels in my inner ear. At night while I was laying in bed I could hear a whoosh with every heart beat as the blood pumped past the partial blockage.[/quote]

That's known as "pulsatile tinnitus". From what I understand, it can be caused by many reasons, not just a blood clot. You're lucky it went away - some people have it indefinitely.

The thing about tinnitus is that it's a broad diagnosis. The stereotype is that it's solely a high-pitched drone; that's a misnomer, there can be many different types of tinnitus.

Did this pulsating noise occur during a stressful time in your life, John? Stress can make the blood thicker, according to research I've seen. The albumin level can go up from stress, as well as other things that can exacerbate issues in fine blood vessels.

Justin
 
[quote author="thermionic"]That's known as "pulsatile tinnitus". From what I understand, it can be caused by many reasons, not just a blood clot. You're lucky it went away - some people have it indefinitely.[/quote]
Uhh, fwiw, think I had that a few nights ago... (yeah, just like everybody suddenly was suffering from RSI a while ago, but no, I'm serious).
Once side, lasted for quite while. Didn't recall it the more recent nights though, I'll have a listen again tonight.
 
Peter - I think it's very common for people to get it for a few minutes at a time. I don't totally understand the mechanism that causes it though - I suspect there could be many. From what I understand, a person isn't classified as a "tinnitus sufferer" until they've had it permanently for 6 months.

Check this out: did you know there's a rare form of tinnitus (objective tinnitus IIRC) where the ear actually makes a noise that's audible to others! You don't want that!

http://en.wikipedia.org/wiki/Tinnitus


BTW - Jaw clenching during sleep can cause tinnitus.

Justin
 
Pulsate tinnitus... thanx for putting a name to that...

Mine was caused by blood clots.. I was stupid and didn't take some time off after a sports injury. I pumped a bunch of blood into wrong places, worse than my inner ear, but I digress.

For Clint, I am not a medical expert but from research on the Internet dealing with clots, I seem to recall the blood vessels in our inner ear are some of the finest blood vessels in our body. If you are getting intermittent partial blockage that might be an early warning sign for circulation issues.

FWIW common aspirin is a blood thinner so next time you are getting such noise, consider popping a couple, but if you have blockages, hearing damage is not the worst case scenario, perhaps the canary in the coal mine.

JR
 
I believe in getting all your vitamins etc. from your food - much better than taking supplements, but having said that, Ginko Biloba is recommended by my GP for improving circulation in fine capillaries etc. It's a blood thinner - try a Google.

You might also want to drink water instead of coffee all the time - like most Dutch people :razz:

If the tinnitus became permanent, there is a drug with minimal side effects that improves circulation in the inner ear.

How long did your tinnitus last for, John?


Justin
 
btw - So as not to scare you anyone, particularly Peter, bear this in mind:

93% of people develop tinnitus if you put them in an anechoic room... I used to be in the 7%, but as I've gotten older I'm now in the 93% :mad: (You can have perfect hearing and have tinnitus btw - the 2 are connected, but can be mutually exclusive).

Anyway, what this proves is that there is a certain amount of plasticity in our auditory mechanism, i.e. it can "tune in" or "tune out", depending on whether we want to focus on something or not.

The upshot of this is two-fold:

a) Don't think about the tinnitus if it comes back - do your very best to ignore it. Understand that it is rarely a sign of bad health. Don't drink too much, or take loads of caffeine. Cut down on cholesterol and keep fit.

b) If it does come back, there are exercises that will enable you to "detune" it - this is known as TRT (Tinnitus Retraining Therapy). Understand that 'web articles paint a far bleaker picture of tinnitus than what actually happens in the real world.


Justin
 
[quote author="thermionic"]

How long did your tinnitus last for, John?


Justin[/quote]

While I wouldn't really call it tinnitus I had audible blood pulsing in one ear for something like one night. As I recall it was gone by morning. It was not a chronic condition but the consequence of a sports injury I didn't manage properly (broken blood vessel in one biceps and traveling blood clots).

To thin my blood, aspirin worked for me.

JR
 
[quote author="JohnRoberts"]

While I wouldn't really call it tinnitus I had audible blood pulsing in one ear for something like one night. As I recall it was gone by morning. It was not a chronic condition but the consequence of a sports injury I didn't manage properly (broken blood vessel in one biceps and traveling blood clots).

To thin my blood, aspirin worked for me.

JR[/quote]

Am I right to assume that the sports injury was a pretty painful one, John? If so, your ESR / Sedimentary Rate may well have been elevated, which is a common cause of temporary pulsatile tinnitus. The aspirin would have helped control the inflammation, bringing your ESR down, in turn creating greater blood flow through the capillaries within your ear - and voila, adios tinnitus! The blood thinning property would also have helped flush out the capillaries.

It should be noted that a high proportion of steady-tone tinnitus cases are deemed to be idiopathic or noise trauma-induced, whereas pulsatile tinnitus is more often a sign of another condition such as inflammation or infection. PT can be idiopathic though, so don't automatically assume it's a sign of something else. Dehydration could probably cause PT by thickening the blood.

Justin
 
Thanks for the info & concern guys - most likely for me just an incident* I couldn't give a proper place, but it's good to see the pleasant exchange of info here (it's not rare on this forum, it's just good to see it works for these kind of topics as well :thumb: )

*: sounded like what you hear after when you ran up a mountain, but just then on one side

Hmm, BTW, about coffee, one time you read it's good for males to have three cups(...mugs?) a day, could lessen the chance you get 'c' and then for other reasons it's better to drink water i.s.o.... and then you read drinking water isn't bringing that much etc etc...

So I don't have the illusion that all 'best-practices' will ever fully agree with each other, but that's a subject of its own.

Regards,

Peter
 
[quote author="thermionic"][quote author="JohnRoberts"]

While I wouldn't really call it tinnitus I had audible blood pulsing in one ear for something like one night. As I recall it was gone by morning. It was not a chronic condition but the consequence of a sports injury I didn't manage properly (broken blood vessel in one biceps and traveling blood clots).

To thin my blood, aspirin worked for me.

JR[/quote]

Am I right to assume that the sports injury was a pretty painful one, John? If so, your ESR / Sedimentary Rate may well have been elevated, which is a common cause of temporary pulsatile tinnitus. The aspirin would have helped control the inflammation, bringing your ESR down, in turn creating greater blood flow through the capillaries within your ear - and voila, adios tinnitus! The blood thinning property would also have helped flush out the capillaries.

It should be noted that a high proportion of steady-tone tinnitus cases are deemed to be idiopathic or noise trauma-induced, whereas pulsatile tinnitus is more often a sign of another condition such as inflammation or infection. PT can be idiopathic though, so don't automatically assume it's a sign of something else. Dehydration could probably cause PT by thickening the blood.

Justin[/quote]

I suspect this is TMI but since you seem interested, the sports injury was not that painful. While playing basketball the bigger guy I was trying to guard under the basket swung his arms wildly and caught me square in my left bicep with his elbow.. he broke a blood vessel in the middle of that muscle. Injuries like that are generally not serious and knit up OK, but I compounded the injury when I foolishly ran 5 miles the next day... I was about 3 miles from my house when I noticed I was pumping blood into my left forearm. Too far to walk home I finished my run..

The hard part was getting all that blood out of where it wasn't supposed to be and back into my veins. My biggest difficulty was clearing clotted blood from the small blood vessels in my hand/fingers. I actually still have some minor nerve damage (tingling in my pinky) years later, from lack of blood flow before I finally cleared all the clots and got blood flowing freely again. In a Rube Goldberg DIY remedy worthy of mention here. I dosed up with garlic and aspirin (and beer) and wrapped my hand in a blood pressure cuff. Then I pressurized my hand to 160# to help break up the clots... Silly sounding but it worked after numerous repetitions.

The noise in my ear a day or two later was a trivial distraction compared to actual nerve damage. In hindsight the traveling clots could have done far worse mischief elsewhere, but I guess they had to pass through the fine blood vessels in my hand so only smaller blood vessels elsewhere would notice them. I was stupid and lucky.

I still play basketball but am more sensitive now to letting my body mend a little longer after insults.

JR
 

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