ERIC Number: EJ944807
Record Type: Journal
Publication Date: 2011-Oct
Abstractor: As Provided
Reference Count: 0
The MOC Reflex during Active Listening to Speech
Garinis, Angela C.; Glattke, Theodore; Cone, Barbara K.
Journal of Speech, Language, and Hearing Research, v54 n5 p1464-1476 Oct 2011
Purpose: The purpose of this study was to test the hypothesis that active listening to speech would increase medial olivocochlear (MOC) efferent activity for the right vs. the left ear. Method: Click-evoked otoacoustic emissions (CEOAEs) were evoked by 60-dB p.e. SPL clicks in 13 normally hearing adults in 4 test conditions for each ear: (a) in quiet; (b) with 60-dB SPL contralateral broadband noise; (c) with words embedded (at -3-dB signal-to-noise ratio [SNR]) in 60-dB SPL contralateral noise during which listeners directed attention to the words; and (d) for the same SNR as in the 3rd condition, with words played backwards. Results: There was greater suppression during active listening compared with passive listening that was apparent in the latency range of 6- to 18-ms poststimulus onset. Ear differences in CEOAE amplitude were observed in all conditions, with right-ear amplitudes larger than those for the left. The absolute difference between CEOAE amplitude in quiet and with contralateral noise, a metric of suppression, was equivalent for right and left ears. When the amplitude differences were normalized, suppression was greater for noise presented to the right and the effect measured for a probe in the left ear. Conclusion: The findings support the theory that cortical mechanisms involved in listening to speech affect cochlear function through the MOC efferent system.
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Authoring Institution: N/A