Effects of Adding Noise to Circuit Model and Numerical Model of Spontaneous Otoacoustic Emissions

Abstract

Spontaneous otoacoustic emissions have long been modeled using self-excited, nonlinear oscillators. The van der Pol oscillator is a common choice, as many of its properties reflect those of SOAEs: both can begin oscillation in the absence of a direct stimulus, both have narrow frequency bands, and both become stable over time, to name a few. Yet such an idealized equation cannot have a one-to-one correspondence with SOAEs in all factors. Many previously used mathematical and circuit models lack the addition of noise to more accurately show how real world SOAEs operate in an organism’s ear, where noise from the environment is almost entirely unavoidable. The inclusion of uniformly distributed noise in both numerical and circuit models of the van der Pol oscillator was studied to determine whether these models can still accurately explicate SOAEs when modified to be more realistic. In both cases, both models retained the attributes of real world SOAEs despite the addition of noise, allowing them to serve as more useful and accurate models of the phenomenon.