Re: Robust method of fundamental frequency estimation.

[Eckard Blumschein <Eckard.Blumschein@xxxxxxxxxxxxxxxxxxxxxxxxxx>]

Richard F. Lyon <DickLyon@xxxxxxx> wrote:

> I assume you mean C. Kaernbach and L. Demany: "Psychophysical
> evidence against the autocorrelation theory of auditory temporal
> processing".

Yes.

>> ... I do not expect a simple mathematical solution at all, because the
>> multipolars within CN do not synchronously respond to the
>> frequency which stimulated the IHCs. Neurons are generally too slow as to
>> directly convey all audible frequencies. Chopper frequencies in the kHz
>> range are impossible due to refractory time. So auditory nerve and cochlear
>> nucleus perform something like down-sampling. So harmony and in particular
>> octave unison are quite natural phenomena. We need not look for their
>> 'learned' basis.
>
> Here I have no idea what you think you're responding to.

To some extent I tried to temper my own ideas
http://iesk.et.uni-magdeburg.de/~blumsche/M277.html
to some extent I uttered an anticipatory antithesis to what meanwhile Martin
Braun and others contributed to this discussion.

I am well aware of e.g. Edward W. Large of Florida Atlantic University who
explains pitch like the result of a comparison between an expected cortical
pattern of excitation and 'phase' of stimulus.

Do not worry about the seeming contradiction between his complex Hopf
oscillator and my insight that we do not need phase of a single signal, so
called linear phase, at all. Relative phase is an apt parameter in case of
comparison between different signals. One may benefit from using complex
calculus
but beware of misinterpreting complex results, cf.
http://iesk.et.uni-magdeburg.de/~blumsche/M283.html.

Acknowledging the role of comparison between upward input and active downward
expectation which is also evident in vision, we should nonetheless not ignore
that down-sampling of frequency is a must in mammal audition, and it
necessarily goes along with something similar to a neural second analysis of an
already mechanically cosine transformed signal. Therefore, I do not see any
alternative to unlearned basic octave unison.

I do dot accept the argument that octave unison must be explained by circular
chroma attributed to thalamus rather than small integer periodicity just because
generalisation over the distance of two octaves was found to be even stronger
than that over the distance of one octave. We should have learned from the
quarrel between Ohm and Seebeck that neural systems can easily be
misinterpreted.

What about the neural mechanisms, I guess we will understand them best if we
imagine evolution like a player who tries to apply, modify, and judge every new
occasionally found principle as universal as possible.

Eckard