Subject: Re: BM motion From: "Richard F. Lyon" <DickLyon@xxxxxxxx> Date: Tue, 13 Nov 2007 20:22:06 -0800 List-Archive:<http://lists.mcgill.ca/scripts/wa.exe?LIST=AUDITORY>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