Re: Pitch and forward masking (Eckard Blumschein )

Subject: Re: Pitch and forward masking
From:    Eckard Blumschein  <Eckard.Blumschein(at)E-TECHNIK.UNI-MAGDEBURG.DE>
Date:    Fri, 16 Jan 2004 12:48:36 +0100

At 10:17 16.01.2004 +0000, Brian C. J. Moore wrote:
...
>So, I don't think that Chen-Gia Tsai's alternative "explanation" of the
>results of Gockel et al. can be correct.

At least, I feel that his criticism might be correct. Chen-Gia just wrote
to me:

I use autocorrelation analysis for studying the multi-pitch effect in
musical sounds with the predominance of upper odd harmonics. For instance,
a complex tone composed of three harmonics at 7f0, 9f0, and 11f0 can elicit
three pitches: a prominent pitch of f0, two weak pitches of 9f0/4 and 9f0/5.
However, this method lacks a physiological basis for auditory temporal
coding at high frequencies (> 4 kHz), because the autocorrelation function
is calculated on the basis of high-frequency harmonics beyond the limits of
phase locking in the auditory nervous system. Therefore, one needs a new
model fusing the temporal and the place representation for extracting
pitches from high-frequency harmonics.

Do you have any idea to justify the autocorrelation analysis that also
relies on high-frequency components?

I will reply to him:

Apparently you are not very interested in my work concerning the
fundamentals of the mathematical fundamentals of signal processing behind
audition. Never mind. Let's only refer to autocorrelation. Do not worry: It
starts with Fourier cosine transform. The next essential step - still
within cochlea - is the one-way rectification. No, I do not attribute the
complete autocorrelation analysis to the brain. I envision just the final
steps to be performed there. It is physiologically plausible to me that
about a third of CN acts almost like a frequency divider. Multipolar
chopper cells tend to very regularly fire with frequencies sufficiently low
for neural frequency analysis. According to the Wiener-Chintchine theorem,
subsequent neural frequency analysis via coincidence detection may complete
a joint autocorrelation involving cochlea and brain together. Thus I
attempt to revitalize the original idea of cepstrum. I just looked for a
translation it into physiology of hearing, and am intrigued how well it
seems to elucidate many psychoacoustical paradoxes. Of course, pitch is not
the whole hearing but an important aspect of it.

Best wishes,
Eckard



Best wishes,
Eckard