Investigation of DPOAE Components in Time and Frequency

DESCRIPTION (provided by applicant): Otoacoustic emissions (OAEs) are signals generated in the cochlea, presumably as a byproduct of active physiological processes responsible for normal functioning of the ear. Distortion product OAEs (DPOAEs) are recorded by stimulating the cochlea simultaneously with two pure tones. A model in which DPOAEs recorded in the ear canal are represented as a composite signal comprised of contributions from several components has been proposed by Talmadge et al., (1998). Research recently has focused on the examination of specific properties of individual DPOAE components identified in this model. The goals of this study are to investigate the effect of input level on the main DPOAE components, and to examine the existence of multiple internal reflections in the cochlea as stimulus level is varied. Additionally, the data obtained during these experiments will allow the estimation of several model parameters. Overall, the results of these studies will improve our understanding of the DPOAE generative mechanisms and the basic mechanics of the cochlea. Such knowledge will invariably improve our ability to use DPOAEs as both a clinical and a research tool.