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Re: Is there considerable phase locking up to 6 kHz?
Title: Re: Is there considerable phase locking up to 6
At 9:53 AM +0100 03/18/2004, Eckard Blumschein wrote:
However, we all should be wary of
thoughtlessly using notions like spectrum
and temporal fine structure.
I'm glad that we have that point of agreement.
Already the fundamentally inappropriate
traditional spectrogram illustrates
that the iteration of a segment of noise without any spectral
introduces an audible spectral signature. Of course, the FCT-based
spectrogram shows a more realistic picture of firing pattern in
auditory nerve. I remind those who do not trust in FCT, because
wrongly put it in the drawer of an exotic mathematical idea while
actually replaces FT, of the need to define what we are talking about
are using terms like spectral
I'm trying to decide whether that comment is directed at me.
Certainly I've always been very careful about concepts such as
spectral components, as I believe the such frequency-domain concepts
often force thinking into wrong directions. I also don't regard
Fourier Cosine Transforms as any more exotic than other mathematical
transforms. But I do mistrust them as auditory models.
Martin Braun is certainly correct in
that, there are at least two main
streams of auditory information within each CN. However, he
ignores tonotopy as long as he doesn't follow my suggestion that place
is the best base for subsequent temporal processing. For more than
century, Fourier analysis and place code were considered the basis
hearing and of related audio technology because alternative temporal
Here we have a different view of the impact of the Fourier
analysis approach and place code on the historical development of
auditory theory. I'm more aligned with a quote that I heard
attributed to Georg von
Békésy: "Dehydrated cats and the application of
Fourier analysis to problems in hearing become more and more a
handicap for progress in hearing research."
As far as I know, temporal models have succeeded more than failed
(that is, temporal models of processing in and beyond the cochlea, not
to be confused with temporal processing of raw sound waveforms).
Spectral models, while widely used, often run into limitations that
make them "fail".
Why not seriously dealing with an unseen
mathematically correct and
physiologically plausible model that unites function of cochlea and
in a somewhat strange hidden manner which is already known as
analysis? It also may elucidate why different codes contribute to a
Cepstral analysis is fine as far as it goes. But it is
rather limiting, as a mathematical framework that stops short of
describing what's going on in detail, essentially ignoring temporal
fine structure on the auditory nerve.
I do not appreciate glossing over FCT as
a red herring since such emotional
arguments are difficult to falsify. Nonetheless, I would hope that
listeners confirm or deny the putative 400/800 Hz confusion. So far, I
only aware of a plausible 50/100 Hz confusion in case of iterated
segments with alternating polarity
inversion (Warren & Wrightson 1981).
OK, this part I'm certain is directed at me, since I mentioned
red herrings. My comment was not directed at the FCT itself,
which is a perfectly fine transform, but rather to the idea that if
you use it then you can ignore questions of temporal fine structure.
Specifically, what I said quoted your assertion, this way ...the idea
that "FCT is the only realistic cochlear transform" is just
a mathematician trying to force a biological system to be something he
can analyze.' I apologize for putting it in such personal