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Posted by izhak 3 days ago

How the cochlea computes (2024)(www.dissonances.blog)
480 points | 148 commentspage 3
amelius 3 days ago||
What does the continuous tingling of a hair cell sound like to the subject?
dfboyd 3 days ago|
tinnitus
xmcqdpt2 3 days ago||
Many versions of this article could be written:

The computer does not do a Fourier transform (FFT computes the discrete Fourier transform)

Spectroscope dont do a Fourier transform (it's actually the short time FT)

The only thing that actually does Fourier transform is a mathematician, with a pen and some paper.

hbarka 2 days ago||
Somewhere here must lie the cure to tinnitus.
Traubenfuchs 2 days ago|
No, tinnitus beyond the cochlea, beyond the hearing nerve even, in some part of the audio processing brain tissue.

Cutting the hearing nerve does not cure tinnitus.

It develops due to a destruction of hearing cells that leads the brain to upregulate gain to catch a weak/absent signal, when the deprivation pattern is just right. (no tinnitus develops when the hearinf nerve is cut -> deprivation pattern matters)

brcmthrowaway 3 days ago||
OT: Does anyone here believe in Intelligent Design?
xeonmc 3 days ago||
As low-level physical mechanistic processes? Absolutely not.

As higher-order, statistically transparent abstract nudges of providence existing outside the confines of causality? Metaphysically interesting but philosophically futile.

jibal 3 days ago||
Hopefully not ... it has been thoroughly debunked, whereas the theory of evolution is supported by massive amounts of data and is the foundation of the entire science of biology.
bloppe 3 days ago||
Man, I've been spreading disinformation for years.
saltcured 3 days ago||
This is one of those pedant vs cocktail chatterer distinctions. It's an interesting dive and gives a nice, triggering, headline.

But, to the vast majority who don't really know or care about the math, "Fourier Transform" is, at best, a totem for the entire concept space of "frequency domain", "spectral decomposition", etc.

They are not making fine distinctions of tradeoffs among different methods. I'm not sure I'd even call it disinformation to tell this hand-wavy story and pique someone's interest in a topic they otherwise never thought about...

rolph 3 days ago||
the closest i have been, was acoustic phase discrimination by owls.

there appears to be no software for this, its all hardware, the signal format flips as it travels through the anatomy.

lukeinator42 3 days ago|||
also, the common ancestor of mammals and birds did not have a tympanic ear, so sound localization evolved differently in the avian vs. mammalian hearing systems. A good review is here: https://journals.physiology.org/doi/pdf/10.1152/physrev.0002.... How the brain calculates interaural time delays is actually an interesting problem as the time delays are so short, that it is less time than a neuron has to fire an action potential.
nakulgarg22 3 days ago|||
This might be interesting for you - https://nakulg.com/assets/papers/owlet_mobisys2021_nakul.pdf

Owls use asymmetric skull structure which helps them in spatial perception of sound.

rolph 3 days ago||
that was the start of it. the offset otic openings result in differential arrival times of the acoustic peaks, thus phase differential.

neurosynaptically, there is no phase, there is frequency shift corresponding to presynaptic intensity, and there is spatio-temporal integration of these signals. temporal integration is where "phase" matters

its all a mix of "digital" all or nothing "gates" and analog frequency shift propagation of the "gate" output.

its all made nebulous by the adaptive, and hysteretic nature of the elements in neural "circuitry"

debo_ 3 days ago||
Fourear transform
superb-owl 3 days ago||
The title seems a little click-baity and basically wrong. Gabor transforms, wavelet transforms, etc are all generalizations of the fourier transform, which give you a spectrum analysis at each point in time

The content is generally good but I'd argue that the ear is indeed doing very Fourier-y things.

anyfoo 3 days ago||
Agree on the click-baity part, but as for being wrong... not if we're really pedantic. As you've said, Gabor and wavelet are basically generalizations of the Fourier Transform, not actually Fourier Transforms. Just like FS/DFT/DTFT aren't really Fourier Transforms either.

On one corner of the square, you have Fourier Transforms, which are essentially contiguous and infinite. On the opposite corner, you have the DFT, which is both finite (or periodic) and discrete. Hearing is more akin to a Fourier Series, which is finite/periodic but contiguous. That's probably not what the article aims at addressing, though.

But then wavelet transforms are different from Fourier Series again, because you have shifted and stretched shapes (some of them quite weird) instead of sinusoids.

But yeah, colloquially, I agree, the ear is indeed doing very Fourier-y things.

fat_cantor 3 days ago||
It's a graduate student writing a journal club article about the Lewicki 2002 paper, which is very good, and whose abstract states the idea more precisely: "The form of the code depends on sound class, resembling a Fourier transformation when optimized for animal vocalizations and a wavelet transformation when optimized for non-biological environmental sounds"
hamonrye 3 days ago||
[dead]
lala_ 3 days ago|
[flagged]