[accountofme]

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)

[tasty_freeze]

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.

[monkeycantype]

I'm wading into an area I'm not expert, not to assert but to ask, I remember having an electro-mechanical object explained to me, I think it was a variant of this: https://www.retrothing.com/2008/05/the-harmonium-a.html

I can roughly recall the mechanism by which it worked, and was told that this was an analog for how the Fourier transformation worked, and I vaguely remember going through one on paper. The spiral of the cochlear seems an analog of how the harmonium works. Does the earlier poster have a point with regard to the cochlear as a physical object performing a Fourier transform (though perhaps not a fast one)?

[woojoo666]

Fourier transform is different from FFT, which is Fast Fourier Transform. FFT is an optimization that involves decomposing a signal into multiple "smaller" signals, recursively performing FFT on those, and then combining the results.

[musicale]

s/FF/F/

[samatman]

The accurate way of saying this is that the cochlear does Fourier analysis.

Folks around here don't handle ambiguity well, and are treating your comment like it's wrong, rather than basically correct except for a harmless conflation of an algorithm for something with the thing itself.

Ah well.

[TaupeRanger]

No, that's also not accurate. Words mean things. We know that parts of the cochlea respond to different frequencies, but that does remotely imply that the auditory system is doing Fourier analysis, which is a high level mathematical transform with a specific set of formulations. "Fourier Analysis" does not describe every possible method of extracting frequency content from a signal.

[samatman]

> Fourier analysis of discharge patterns in response to sinusoidal acoustic stimulation provides a consistent and repeatable measure of response phase and amplitude. The Journal of the Acoustical Society of America 58, 867 (1975); https://doi.org/10.1121/1.380735

> sinusoidal frequency domain decomposition of sound waves is a key mechanical phenomenon exploited by our hearing system, leading to in effect a frequency domain transformation of the temporal pattern of compressions and rarefactions that we term sound. https://uncommondescent.com/video/hearing-the-cochlea-the-fr...

That one has a video.

Your case is roughly as incoherent as one which claims that a thrown ball does not perform Newtonian physics. It doesn't have to.

Now that we've disposed of the nonsense that cochlear response is not meaningfully modeled with Fourier analysis, interested parties might have fun with research into all the ways this model is not perfect. I've got a paper loaded in my reader claiming it's actually wavelet analysis, for when I have time and inclination to read it.

[accountofme]

thanks for your reply :)

You are right. My apologies for the conflation.