Re: model of the cochlea

["Richard F. Lyon" <DickLyon@xxxxxxx>]

Fred,

The trouble with the Peterson & Boget model (like 
the Wegel & Lane 1924, Zweig Lipes & Pierce 1975, 
and some others, if I understand correctly) is 
that it is a one-dimensional model, based on a 
long-wave approximation to the underlying 
hydrodynamics, even though the wavelength in the 
cochlea are known to be way too short for that in 
the region near resonance.  So an accurate 
solution to those equations in not a good cochlea 
model.

Depending on what your goals are in terms of 
accuracy or usefulness of a model, I might be 
able to recommend some alterative approaches 
(based on 2D model or more abstract model), and 
maybe some code.

Malcolm Slaney has published code for my old 
model based on an adaptation of the 
one-dimensional model; it doesn't give an 
accurate solution of the equations, but might be 
an acceptable model.  I think it's all stil 
available, here: 
http://cobweb.ecn.purdue.edu/~malcolm/interval/1998-010/

Dick


At 8:58 PM -0400 9/15/07, Fred Herzfeld wrote:
> Hello list,
>
> I am  interested in obtaining a source program 
> (or any ideas) for determining the 175 outputs 
> of a transmission line model of the cochlea as 
> represented in:
>
>    	An integrable model for the basilar membrane
> 	M.R. Schroeder
> 	JASA 1973 53(2) 429-434
>
> 	A Dynamical Theory of the Cochlea
> 	L.C. Peterson; B.P. Bogert
> 	JASA 1950 22(3) 369-381
>
> 	Determination of the effects of 
> Dissipation in the cochlea Partition by Means of 
> a Network	 Representing the Basilar Membrane
> 	B.P. Bogert
> 	JASA 1951 23(2) 151-154
>
> The present plan is to use a differential 
> equation routine such as RKG to obtain outputs 
> at very small time increments along the entire 
> 175 or more sections. Although certainly not in 
> real time this will be the section between the 
> front end (encoding each source position from 
> HRTF like data) and the processing to required 
> to simulate the 3-D positions in the CNS, and 
> then follow this up by determining the actual 
> signal originating ONLY from a particular 3-D 
> position in space. This will complete the total 
> model. At present the DE section is simulated 
> with "representative" outputs.
>
> Any ideas or suggestion on the above will be very much appreciated.
>
> Fred
>
> --
> Fred Herzfeld, MIT '54
> 78 Glynn Marsh Drive #59
> Brunswick, Ga.31525
> USA