Sponsor
Portland State University. Department of Speech Communication
First Advisor
Douglas Martin
Term of Graduation
Spring 1995
Date of Publication
4-28-1995
Document Type
Thesis
Degree Name
Master of Science (M.S.) in Speech Communication: Speech and Hearing Sciences
Department
Speech Communication
Language
English
Subjects
Impedance audiometry, Otoacoustic emissions, Middle ear
DOI
10.15760/etd.7095
Physical Description
1 online resource (2, ii, 41 pages)
Abstract
The middle ear system is a vital component in the propagation mechanism of otoacoustic emissions. As such, investigation of the effect of variation in middle ear impedance on the measurement of emissions is warranted.
Distortion product otoacoustic emissions (DPOAEs) have gained recognition as a means of gaining frequency specific information on auditory function. As the effects of changes in middle ear impedance will vary as a function of frequency, a clear definition of the relationship between middle ear impedance and DPOAE amplitude across the frequency spectrum is needed.
Twenty adults (ages 20-37) with normal hearing and normal middle ear function were selected as subjects. Commercially available equipment (Virtual 330) was used to measure the DPOAEs on all subjects. The unit was modified to change canal pressure by coupling the probe to the pressure pump of a clinical acoustic immittance system. One ear from each subject was randomly selected for measurement and each subject was tested under five pressure conditions: +200, O, -200, -300, -400 daPa. The mean frequency of the fl/f2 tone pairs swept from 500 to 8000 Hz.
Results indicate that changes in ear canal pressure can effect the amplitude of DPOAEs. Alteration of ear canal pressure resulted in decreased emission amplitude. This effect was found to differ as a function of eliciting frequency with the greatest reduction in amplitude with the mean of the primaries at 500 Hz. Less variation was noted across the ear canal pressures with the higher frequency stimuli. These results are consistent with previous findings reported regarding the effects of impedance changes on spontaneous and transiently evoked otoacoustic emissions.
Rights
In Copyright. URI: http://rightsstatements.org/vocab/InC/1.0/ This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
Persistent Identifier
https://archives.pdx.edu/ds/psu/30183
Recommended Citation
Head, Jodi L., "The Effects of Ear Canal Pressure Variation on Distortion Product Otoacoustic Emissions" (1995). Dissertations and Theses. Paper 5219.
https://doi.org/10.15760/etd.7095
Comments
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