3 ms·

In your example saying that the ear doesn’t work as an FFT, I think you’re confusing physical processes (the ear) with perceptual processes (psychoacoustics and

by klik99 6y ago

In your example saying that the ear doesn’t work as an FFT, I think you’re confusing physical processes (the ear) with perceptual processes (psychoacoustics and interaction between the brain and ear). The cochlea itself is a physical FT, based on resonances in the thickness at various points. That gets passed to the brain as basically sine-frequency data. The autocorrelation part comes in when the brain processes this and actually reinforces it by feeding back signals it thinks are peaking back into the inner ear. (Edit) also this is a really fascinating and enlightening way of viewing it - didn’t mean to imply otherwise with this quibble :)

acjohnson55 6y ago
IIRC, that's probably not quite true. It's been about a decade since I studied hearing, but my understanding is that the idea of the cochlea being a physical FT (e.g. the place theory of hearing) doesn't explain some phenomena, which also probably aren't psychoacoustic. https://en.m.wikipedia.org/wiki/Temporal_theory_(hearing) https://en.m.wikipedia.org/wiki/Temporal_theory_(hearing)
- klik99 6y ago
  I'll read more about it, but the thickness/stiffness of the cochlea resonates at frequencies with sensitivity that matches our ability to distinguish frequencies - it has been removed from the inner ear and resonance tested outside of the context of other processes. Interesting that it doesn't explain some phenomena, but are the temporal theory and place theory mutually exclusive? (Edit) After reading a bit more, it seems to make more sense that it's a combination of both, as the resonance on the cochlea is likely not 100% accurate, and conversely the impulses from peaks would tend to be around the areas of resonance, so rather than being mutually exclusive it makes sense these two effects work in parallel. Modern research suggests that the perception of pitch depends on both the places and patterns of neuron firings. Place theory may be dominant for higher frequencies.[4] However, it is also suggested that place theory may be dominant for low, resolved frequency harmonics, and that temporal theory may be dominant for high, unresolved frequency harmonics.[5]

by klik99 6y ago

acjohnson55 6y ago

IIRC, that's probably not quite true. It's been about a decade since I studied hearing, but my understanding is that the idea of the cochlea being a physical FT (e.g. the place theory of hearing) doesn't explain some phenomena, which also probably aren't psychoacoustic. https://en.m.wikipedia.org/wiki/Temporal_theory_(hearing) https://en.m.wikipedia.org/wiki/Temporal_theory_(hearing)

klik99 6y ago
I'll read more about it, but the thickness/stiffness of the cochlea resonates at frequencies with sensitivity that matches our ability to distinguish frequencies - it has been removed from the inner ear and resonance tested outside of the context of other processes. Interesting that it doesn't explain some phenomena, but are the temporal theory and place theory mutually exclusive? (Edit) After reading a bit more, it seems to make more sense that it's a combination of both, as the resonance on the cochlea is likely not 100% accurate, and conversely the impulses from peaks would tend to be around the areas of resonance, so rather than being mutually exclusive it makes sense these two effects work in parallel. Modern research suggests that the perception of pitch depends on both the places and patterns of neuron firings. Place theory may be dominant for higher frequencies.[4] However, it is also suggested that place theory may be dominant for low, resolved frequency harmonics, and that temporal theory may be dominant for high, unresolved frequency harmonics.[5]