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.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Small Research Grants (R03)
Project #
7R03DC005692-02
Application #
6912308
Study Section
Special Emphasis Panel (ZDC1-SRB-O (22))
Program Officer
Donahue, Amy
Project Start
2004-01-01
Project End
2006-12-31
Budget Start
2004-08-01
Budget End
2004-12-31
Support Year
2
Fiscal Year
2004
Total Cost
$50,968
Indirect Cost
Name
Northwestern University at Chicago
Department
Other Health Professions
Type
Schools of Arts and Sciences
DUNS #
160079455
City
Evanston
State
IL
Country
United States
Zip Code
60201
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Shaffer, Lauren A; Dhar, Sumitrajit (2006) DPOAE component estimates and their relationship to hearing thresholds. J Am Acad Audiol 17:279-92
Dhar, Sumitrajit; Shaffer, Lauren A (2004) Effects of a suppressor tone on distortion product otoacoustic emissions fine structure: why a universal suppressor level is not a practical solution to obtaining single-generator DP-grams. Ear Hear 25:573-85