Comments on octave equivalence

Here is something I found on

http://www.sweeney-todd.freeserve.co.uk/temper/no-frames/micro.htm

I'd be interested to hear comments from Paul, et al, on this:

An interesting consideration is the phenomenon of the octave. Why is it, when we consider the audible frequency range from 20Hz to 20 KHz, we perceive a series of points along this scale that we can consider as having the same "quality" while patently being a different note? Part of the explanation may be that if we take a bi-lateral cross-section through the cochlea, that part of the ear's mechanism responsible for converting acoustic energy into electrical impulses, it reveals a spiral shape which can be described mathematically by a Fibonacci Series; the same maths govern the principles of the harmonic series. Neuro-pathology of the ear shows that octaves are decoded at the same point in each layer of the spiral. Some experts maintain that if the cochlea was a straight cone, rather than a tightly-wound spiral, we would have no perception of the octave at all; all we would hear would be a series of successively rising tones.

--- In tuning@y..., "genewardsmith" <genewardsmith@j...> wrote:
> Here is something I found on
>
> http://www.sweeney-todd.freeserve.co.uk/temper/no-frames/micro.htm
>
> I'd be interested to hear comments from Paul, et al, on this:
>
> An interesting consideration is the phenomenon of the octave. Why
>is it, when we consider the audible frequency range from 20Hz to 20
>KHz, we perceive a series of points along this scale that we can
>consider as having the same "quality" while patently being a
>different note? Part of the explanation may be that if we take a bi-
>lateral cross-section through the cochlea, that part of the ear's
>mechanism responsible for converting acoustic energy into electrical
>impulses, it reveals a spiral shape which can be described
>mathematically by a Fibonacci Series; the same maths govern the
>principles of the harmonic series.

Why does the author bring this in at this point? Seems fishy . . .

>Neuro-pathology of the ear shows that octaves are decoded at the
>same point in each layer of the spiral.

This was a startling claim when I first read this on this website.
Subsequently scouring the literature failed to provide any support
for this claim.

>>impulses, it reveals a spiral shape which can be described
>>mathematically by a Fibonacci Series; the same maths govern
>>the principles of the harmonic series.
>
>Why does the author bring this in at this point? Seems fishy . . .

Sure does.

>>Neuro-pathology of the ear shows that octaves are decoded at the
>>same point in each layer of the spiral.
>
>This was a startling claim when I first read this on this website.
>Subsequently scouring the literature failed to provide any support
>for this claim.

I've never heard of this, either. Even if it were true, it alone
would fail to correlate with anything perceptual on the order of
octave equivalence. Finally, one would still have to explain why
such a structure evolved in the first place.

-Carl

Actually I was in Walter o' Connells class and he played a microtonal scale going up against a
drone and he asks us to raise our hand when we got to the octave. At one point i think we all
raised our hand. We were at the .618...... of the octave

clumma wrote:

> >>impulses, it reveals a spiral shape which can be described
> >>mathematically by a Fibonacci Series; the same maths govern
> >>the principles of the harmonic series.
> >
> >Why does the author bring this in at this point? Seems fishy . . .
>
> Sure does.
>
> >>Neuro-pathology of the ear shows that octaves are decoded at the
> >>same point in each layer of the spiral.
> >
> >This was a startling claim when I first read this on this website.
> >Subsequently scouring the literature failed to provide any support
> >for this claim.
>
> I've never heard of this, either. Even if it were true, it alone
> would fail to correlate with anything perceptual on the order of
> octave equivalence. Finally, one would still have to explain why
> such a structure evolved in the first place.
>

-- Kraig Grady
North American Embassy of Anaphoria island
http://www.anaphoria.com

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