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Scientists discover mechanism of hearing

news.ohsu.edu

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Re: Scientists discover mechanism of hearing

#21

Post by thelittleone »

ncr100 wrote: post #8
swayvil wrote: post #6

Was it always a big mystery? Or did we think we understood it the whole time, but only just recently discovered that we actually didn't?

Mystery. According to the article and the paper we now have a clear understanding of how it works - the proteins in worms (which are similar to humans in their hearing structures) and their function. So, unless I misread it, we absolutely know how sound > neural impulse works. More: > The initial step in the sensory transduction pathway underpinning hearing and balance in mammals involves the conversion of force into…

Wow. For some reason I had always assumed worms cannot hear.

Re: Scientists discover mechanism of hearing

#22

Post by lr4444lr »

formerly_proven wrote: post #13

Hearing is kind of fascinating if you calculate the power supplied to the eardrum in the ~0 dB range, we're talking about attowatts of sound power generating movements in the single-digit nanometer range, which is still picked up and converted to a neuronal response. Meanwhile the whole thing suppresses the far greater pressure fluctuations due to your heartbeat and other movements quite well, and can reasonably cope…

How do you know those noises are suppressed and not just neurologically "filtered out" by the auditory cortex?

Re: Scientists discover mechanism of hearing

#23

Post by accountofme »

TaupeRanger wrote: post #20
xani_ wrote: post #18

Earlier quoted context omitted.

And it does FFT in realtime too

It does extract frequency information but not via FFT. Just like the brain computes but not via Turing Machine.

The brain doesn't compute it, the cochlear is an fft! It is a cone shaped structure (that is curled up) that is covered in hairs and neurons. The fatter end is used for low freq and the thinner end is used for hi freq. So the brain takes audio in the frequency domain, not as continuous samples!

(I did an Anatomy degree almost 20years ago now, all from memory)

Re: Scientists discover mechanism of hearing

#24

Post by 1letterunixname »

WHAT?! :> I'm at ACL and can't hear a fucking thing. ;)

I wonder about the limits of the muscles of the eardrum (TT and stapedius) to prevent hearing damage. For example, I recall awaking one morning being unable to hear because those muscles were isometrically flexing to a degree that prevented the eardrum from move normally. I thought I lost my hearing but then they started to relax over a few minutes.

I don't know if anyone else can, but I can consciously make both eardrums vibrate creating a sound like a rumble.

Last thing: I can hear my left eye move. I have a SCDS that I was able to identify myself as it's the only condition with this rare symptom. There is a tiny hole in the thin, porous bone between my inner ear and brain. It can be fixed surgically but requires brain surgery that effectively jacks the brain up and out of the way to be repaired by a surgical otolaryngologist. Eating chips is horrendously loud. Exercising leads to hearing my pulse. The risks of surgery though make me think it's worth enduring annoyances, although I don't know if it's causing extra cognitive load (distraction filtering) or balance problems. Oh and tinnitus from hell.. REEEEEE.

Re: Scientists discover mechanism of hearing

#25

Post by vanderZwan »

thelittleone wrote: post #21
ncr100 wrote: post #8

Earlier quoted context omitted.

Mystery. According to the article and the paper we now have a clear understanding of how it works - the proteins in worms (which are similar to humans in their hearing structures) and their function. So, unless I misread it, we absolutely know how sound > neural impulse works. More: > The initial step in the sensory transduction pathway underpinning hearing and balance in mammals involves the conversion of force into…

Wow. For some reason I had always assumed worms cannot hear.

I never thought about it before but if someone had asked me I probably would have guessed the same - humans are probably biased to assume hearing must involve ears.

OTOH, detection of mechanical vibrations seems like the kind of adaptation to evolve early. Hearing is in some sense just a refinement of that, so at the very least the groundwork for it must be old.

Re: Scientists discover mechanism of hearing

#26

Post by 9wzYQbTYsAIc »

1letterunixname wrote: post #24

WHAT?! :> I'm at ACL and can't hear a fucking thing. ;) I wonder about the limits of the muscles of the eardrum (TT and stapedius) to prevent hearing damage. For example, I recall awaking one morning being unable to hear because those muscles were isometrically flexing to a degree that prevented the eardrum from move normally. I thought I lost my hearing but then they started to relax over a few minutes. I don't know…

> I can consciously make both eardrums vibrate creating a sound like a rumble

I can as well when I consciously try to pop my ear drums.

Re: Scientists discover mechanism of hearing

#27

Post by BurningFrog »

formerly_proven wrote: post #13

Hearing is kind of fascinating if you calculate the power supplied to the eardrum in the ~0 dB range, we're talking about attowatts of sound power generating movements in the single-digit nanometer range, which is still picked up and converted to a neuronal response. Meanwhile the whole thing suppresses the far greater pressure fluctuations due to your heartbeat and other movements quite well, and can reasonably cope…

Our hearing is vastly better than our sight.

Human hearing can distinguish thousand of individual frequencies, with the highest frequency 1000x the lowest.

Human sight can distinguish 3 broad frequency regions, with the highest frequency 2x the lowest.

Where vision shines is distinguishing where the signal comes from.

Re: Scientists discover mechanism of hearing

#28

Post by myself248 »

thelittleone wrote: post #21
ncr100 wrote: post #8

Earlier quoted context omitted.

Mystery. According to the article and the paper we now have a clear understanding of how it works - the proteins in worms (which are similar to humans in their hearing structures) and their function. So, unless I misread it, we absolutely know how sound > neural impulse works. More: > The initial step in the sensory transduction pathway underpinning hearing and balance in mammals involves the conversion of force into…

Wow. For some reason I had always assumed worms cannot hear.

Smell (chemical environment) was probably the "original" sense, followed quickly by touch (slow macro pressure) and hearing (fast micro pressure). Pretty much every animal has those, even if they lack the brains to do much sophisticated with them.

Sight came way, way, way, way, way, way, way later. Encoding language in sounds is an even more recent innovation, in the grand scheme.

This may also be why we have such trouble assigning words to smells, and you can't write a poem to replace a hug, for instance. They're processed by entirely different, and far more primal, parts of the brain than language.

Re: Scientists discover mechanism of hearing

#29

Post by tasty_freeze »

accountofme wrote: post #23
TaupeRanger wrote: post #20

Earlier quoted context omitted.

It does extract frequency information but not via FFT. Just like the brain computes but not via Turing Machine.

The brain doesn't compute it, the cochlear is an fft! It is a cone shaped structure (that is curled up) that is covered in hairs and neurons. The fatter end is used for low freq and the thinner end is used for hi freq. So the brain takes audio in the frequency domain, not as continuous samples! (I did an Anatomy degree almost 20years ago now, all from memory)

The person you are responding to is right and your assertion is incorrect. The person you replied to knows the ear delivers a frequency domain representation. They were disagreeing with the FFT part.

The FFT is a specific mathematical construction that carries out a Fourier Transform efficiently through a hierarchy of "butterfly" steps. The ear has no such thing. It is just ~20,000 hair cells, each resonant to a specific frequency. That is, each computation is local, very unlike the FFT.

Re: Scientists discover mechanism of hearing

#30

Post by thelittleone »

vanderZwan wrote: post #25
thelittleone wrote: post #21

Earlier quoted context omitted.

Wow. For some reason I had always assumed worms cannot hear.

I never thought about it before but if someone had asked me I probably would have guessed the same - humans are probably biased to assume hearing must involve ears. OTOH, detection of mechanical vibrations seems like the kind of adaptation to evolve early. Hearing is in some sense just a refinement of that, so at the very least the groundwork for it must be old.

Remarkable nature. Whenever my daily problems get on top of me, I like to spend a moment to think about the absurd but beautiful reality that we creatures exist and that we're hurtling through space. And now... that worms can hear... in a way similar enough to humans.
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