Re: BM motion

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

No matter how the nonlinearity affects the tone amplitudes, the sum 
of two sinusoids of different frequencies is easily distinguishable 
from a larger single sinusoid, through the temporal pattern, which 
will be appararent in the auditory nerve firing-time patterns, even 
when both frequencies are higher than can be coded by synchrony.

As to the nonlinearity, it shows up clearly in the mechanics, when 
the OHCs are functioning, and it's not hard to see how OHCs in one 
region can change the response to other tones that travel through 
that region to be localized further on; that is, how high-f can 
suppress low-f if not too much lower.  The other direction works 
slightly differently, but the key is that different frequencies share 
the same traveling wave medium that amplifies them, so you get 
suppression.  There may yet be mysteries in the micromechanical 
details, but not in the overall functional effect.

Matt, is the "'frequency specificity' mystery" something that you 
find in the literature?  Or do you just mean you haven't found a 
clear enough explanation?

Dick