Subject: Re: Rationale for Critical Bands From: Etienne Gaudrain <et.gaudrain@xxxxxxxx> Date: Tue, 15 Jun 2010 10:16:54 +0100 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>Hi, 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? Cheers, -Etienne 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. > > Dick > > > 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 >> evidence for. >> >> 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. >> >> Dan -- Etienne Gaudrain, PhD MRC Cognition and Brain Sciences Unit 15 Chaucer Road Cambridge, CB2 7EF UK Phone: +44 1223 355 294 Fax (unit): +44 1223 359 062