Re: Rationale for Critical Bands

[Etienne Gaudrain <et.gaudrain@xxxxxxx>]

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