Two-tone suppression in a nonlinear model of the basilar membrane

Abstract

Several aspects of two‐tone suppression in auditory‐nerve fibers have been reproduced in a nonlinear computational model for motion of the basilar membrane. In the model, a distinction is made between mechanical nonlinearity (related in the model to membrane velocity) and neural excitatory signal (related in the model to first or second spatial derivative of membrane displacement). For f₁ (frequency of exciting tone) equal to CF (characteristic frequency), the model successfully reproduces the physiologically observed distinction between f₂ (frequency of suppressing tone) greater than CF and f₂f₂≳CF suppression is related to the intensity ratio of suppressor to excitor, while for f₂f₁ and f₂ components of response to a two‐tone input reveals features of the system that should be amenable to confirmation in future electrophysiological experiments.