A simple model of cochlear micromechanics in the mammal and lizard.

A model is presented which is a simple representation of cochlear micromechanics in the lizard and mammal. The model is a linear, time-invariant mechanical system, consisting of two coupled mechanical filters. It is capable of a sharply tuned first and second filter, consistent with the sharply tuned basilar membrane and auditory nerve fibers in the mammal. When parameters are adjusted for the alligator lizard (Gerrhonotus multicarinatus), the model generates a sharply tuned second filter without a sharply tuned first filter. In the alligator lizard, the auditory nerve fibers are sharply tuned but the basilar membrane is not. The model supports the hypothesis that cochlear transduction is not fundamentally different in the mammal and the alligator lizard.