Nonlinear Waves in the Ear and Sound Signal Processing
Jack Xin, Ph.D.

Professor of Mathematics and ICES (Institute for Computational Engineering

and Sciences), University of Texas, Austin

 
Abstract

We present a class of dispersive nonlinear nonlocal partial differential equations (PDEs) modeling mechanics and neural functions of the inner ear, then discuss analytical and numerical properties of wave like solutions under single and multiple frequency sound inputs. The solutions reveal two tone and three tone suppression effects in qualitative agreement with cat auditory neural data. An associated nonlinear phenomenon at the perception level is masking, namely, an audible sound becomes inaudible in the presence of another sound. We introduce a PDE based two level psychoacoustic model on tonal masking of banded noise, and relate it to perceptual coding in digital music (MP3).