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dc.contributor.advisorGlattke, Theodore J.en_US
dc.contributor.authorHarris, Frances Pauline.
dc.creatorHarris, Frances Pauline.en_US
dc.date.accessioned2011-10-31T17:09:34Z
dc.date.available2011-10-31T17:09:34Z
dc.date.issued1988en_US
dc.identifier.urihttp://hdl.handle.net/10150/184483
dc.description.abstractDistortion-product emissions (DPEs) are tonal responses that may be detected in the ear canal when the ear is stimulated simultaneously by two tones that are closely spaced in frequency. In experimental animals, DPEs are reduced in amplitude or are eliminated when cochlear function is disrupted. This association has not been investigated in human subjects. This study was designed to investigate the relation of cochlear status, as determined by pure-tone behavioral thresholds, to DPE amplitude in human subjects. Forty men were selected as subjects. Twenty had normal hearing and 20 had high-frequency sensorineural hearing loss. Pure-tone behavioral thresholds were determined using conventional audiometric procedures for eight frequencies from 750 to 8000 Hz. DPEs were generated in the test ear of each subject by stimulating the ear with two tones, f1 and f2. The stimuli were selected to approximate audiometric test frequencies. Responses were detected by a sensitive microphone that was placed in the ear canal and were extracted by spectral analysis. Results of the study indicated that DPE amplitude was associated with pure-tone threshold. When audiometric threshold was ≤10 dB HL, DPEs could be elicited at all test frequencies for 98% of subjects in both groups. Mean maximum emission amplitude ranged from 3 to 13 dB SPL across frequency. When pure-tone threshold was above 50 dB HL, DPEs were absent or were significantly attenuated. DPEs varied in amplitude when audiometric threshold was between these two extremes. The association of DPE amplitude were pure-tone threshold was frequency specific. DPE amplitude was maximal when pure-tone thresholds were ≤10 dB HL and decreased as pure-tone behavioral threshold increased in the same subject. Repetition of the DPE protocol with five subjects from each group during separate test sessions indicated that the results were reliable over time. Results of the study have clinical implications. The technique may have potential as a noninvasive means of monitoring the status of the cochlea in human subjects.
dc.language.isoenen_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.subjectAudiometry.en_US
dc.subjectElectrocochleography.en_US
dc.titleDistortion-product emissions and pure-tone behavioral thresholds.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.identifier.oclc701366634en_US
thesis.degree.grantorUniversity of Arizonaen_US
thesis.degree.leveldoctoralen_US
dc.contributor.committeememberHixon, Thomas J.en_US
dc.contributor.committeememberHodgson, William R.en_US
dc.contributor.committeememberBurd, Gail D.en_US
dc.identifier.proquest8824275en_US
thesis.degree.disciplineSpeech and Hearing Sciencesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.namePh.D.en_US
refterms.dateFOA2018-06-16T15:14:24Z
html.description.abstractDistortion-product emissions (DPEs) are tonal responses that may be detected in the ear canal when the ear is stimulated simultaneously by two tones that are closely spaced in frequency. In experimental animals, DPEs are reduced in amplitude or are eliminated when cochlear function is disrupted. This association has not been investigated in human subjects. This study was designed to investigate the relation of cochlear status, as determined by pure-tone behavioral thresholds, to DPE amplitude in human subjects. Forty men were selected as subjects. Twenty had normal hearing and 20 had high-frequency sensorineural hearing loss. Pure-tone behavioral thresholds were determined using conventional audiometric procedures for eight frequencies from 750 to 8000 Hz. DPEs were generated in the test ear of each subject by stimulating the ear with two tones, f1 and f2. The stimuli were selected to approximate audiometric test frequencies. Responses were detected by a sensitive microphone that was placed in the ear canal and were extracted by spectral analysis. Results of the study indicated that DPE amplitude was associated with pure-tone threshold. When audiometric threshold was ≤10 dB HL, DPEs could be elicited at all test frequencies for 98% of subjects in both groups. Mean maximum emission amplitude ranged from 3 to 13 dB SPL across frequency. When pure-tone threshold was above 50 dB HL, DPEs were absent or were significantly attenuated. DPEs varied in amplitude when audiometric threshold was between these two extremes. The association of DPE amplitude were pure-tone threshold was frequency specific. DPE amplitude was maximal when pure-tone thresholds were ≤10 dB HL and decreased as pure-tone behavioral threshold increased in the same subject. Repetition of the DPE protocol with five subjects from each group during separate test sessions indicated that the results were reliable over time. Results of the study have clinical implications. The technique may have potential as a noninvasive means of monitoring the status of the cochlea in human subjects.


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