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Re: Rationale for Critical Bands
Just to add more confusion, I was wondering about the phase response of
the auditory filters. I've always considered that a bandwidth was
related to the magnitude response, so critical bandwidth would be
oblivious of any phase curvature within a filter, while "auditory
filters" would (should) include this phase response.
I realize now that I may have been wrong as the phase response likely
originates in the cochlea, isn't it?
PS: glad to see the cochlear modellers back on the auditory list ;-)
On 15/06/2010 02:45, Richard F. Lyon wrote:
Dan, the situation is indeed complicated, but I don't think there's
much actual disagreement.
I don't think you'll find any serious scientists placing "the burdon
of explaining auditory perception almost entirely upon the cochlea"
even though it is as you say "the most-studied and well-understood
component of the auditory system." There's an awful lot about hearing
that can only be explained in terms of several subsequent levels of
processing, and much that can't yet really be explained at all.
For simple phenomena related to the critical band, however,
understanding the form of the cochlear filter seems to be enough, or
almost enough. The question of whether an auditory filter model can
fit both the psychophysical data as well as the
biomechanical/neurophysiological data has often been openly discussed;
it is not a totally settled question, nor an ignored question. The
result so far seems to be that a good fit in one domain can be at
least plausible in the other.
In my own recent work, I've been promoting a form of cochlear model
that seems to do well on both; that is, it gives excellent fits to
masking data, with few parameters (about like gammachirp or a little
better), and also has structural relations to the underlying
traveling-wave mechanics. Unfortunately, I don't have any journal
articles on it; but I can send you some stuff from a workshop talk and
recent conference talks if you're interested.
At 9:07 AM +0800 6/15/10, Daniel Bowling wrote:
Thanks to all who responded.
In addition to the public posts I have received several private ones
and I think it is safe to say that there is a good deal of
disagreement regrading this matter.
My concern is that research has placed the burdon of explaining
auditory perception almost entirely upon the cochlea, the
most-studied and well-understood component of the auditory system.
Whether the idea is 'critical bands' or 'auditory filters', the
bottom line seems to be the same: the results of the psychoacoustic
experiments are explained by the physical interaction of vibrations
of the BM. This is the claim I am wondering if there is direct
Although cochlear models are of great interest, it is not clear to me
how demonstrating that roex (or gammachirp) functions are capable of
approximating BM motion data explains the perceptual phenomena in
question. It is likely that I have failed to come to grips with the
implications of these models. However, if cochlear models do hold the
key to understanding why we hear what we do, I would greatly
appreciate a presentation of the basic argument in simple enough
terms to inspire a student to expend the considerable time and energy
required to master an understanding of them.
Etienne Gaudrain, PhD
MRC Cognition and Brain Sciences Unit
15 Chaucer Road
Cambridge, CB2 7EF
Phone: +44 1223 355 294
Fax (unit): +44 1223 359 062