Nonlinearities of evoked otoacoustic emissions analyzed by means of a deconvolution procedure

Abstract

Evoked otoacoustic emissions were measured with clicks and short duration tone bursts at intensities ranging from 0–50 dB HL, in normal hearing subjects. Both the initial acoustic transient and the physiological response were measured and stored. This enables the computation of the deconvolution between cochlear response and input stimulus. In a first experiment, the rationale was the following: Does a simple model (the system's impulse response) explain the input‐output relationship with these stimuli? Comparison of the deconvolutions obtained from click‐evoked responses with those evoked by tone bursts reveals that, to a good approximation, the impulse response is a reasonable description of the system's dynamical aspects, at a given stimulus intensity. In a second series of experiments, responses and their deconvolutions were analyzed in more detail across the intensity range. Results show that this view is definitely too simplistic; significant deviations from linearity are observed. These deviations ...