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Article
Evaluation of distortion products produced by the human auditory system
Hearing Research (2004)
  • Shaum P. Bhagat, Louisiana State University and Agricultural and Mechanical College
  • Craig A. Champlin, University of Texas at Austin
Abstract
During the simultaneous monaural presentation of two primary tones, distortion products can be measured acoustically in the ear canal (DPOAEs) and electrically as auditory evoked potentials (DPAEPs). The purpose of this investigation was to elucidate the sources of nonlinearity within the human auditory system responsible for generating quadratic (QDT) and cubic (CDT) difference tones. Measurements of DPOAEs and DPAEPs were obtained from 24 normal-hearing adults (12 male) in conditions with and without presentation of a 60 dB SPL contralateral noise. The effects of primary-tone signal duration and mode of presentation on measurements of DPAEPs were also examined. Results indicated that overall, both acoustic and electric distortion products were suppressed during presentation of a contralateral noise. Increases in the duration of the primary tones caused increases in DPAEP amplitudes. A greater proportion of individuals exhibited DPAEPs with monotic compared to dichotic presentation of the primary tones. The findings of the investigation supported the conjecture that a cochlear nonlinearity produced CDT acoustic and electric distortion products. Evidence concerning the origin of the QDT DPAEP was inconclusive, and contributions from both cochlear and neural nonlinear sources could not be ruled out.
Keywords
  • Distortion products,
  • Auditory evoked potentials,
  • Otoacoustic emissions,
  • Cubic difference tone,
  • Quadratic difference tone
Publication Date
July, 2004
DOI
10.1016/j.heares.2004.04.005
Publisher Statement
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Citation Information
Shaum P. Bhagat and Craig A. Champlin. "Evaluation of distortion products produced by the human auditory system" Hearing Research Vol. 193 Iss. 1-2 (2004) p. 51 - 67 ISSN: 1878-5891
Available at: http://works.bepress.com/shaum-bhagat/22/