Interaction phenomena in a model of mechanical to neural transduction in the ear

Abstract

We describe a model for the transduction of the basilar membrane displacements into activity of the auditory nerve fibers. The model consits of two parts: a one-dimensional model of basilar membrane motions and a model of sensory receptors. The first part is a linear functional model which gives the electrical analog of the displacement patterns of the basilar membrane. The second part is a non-linear physical model which is mainly based on the assumption that information issued from the two kinds of hair cell receptors interacts electrically. The model is shown to reproduce the excitation patterns of single auditory nerve fibers in response to simple input signals (one and two-tone stimuli) or to inferred trapezoidal displacements of the basilar membrane. A second set of experiments is described to show how useful such a model can be for the understanding of complex sound coding. We present results for a speech-like single formant input sound paying special attention to the fundamental frequency representation in the discharge patterns of our simulated fibers.