The MOC reflex during active listening to speech

Angela C. Garinis, Theodore Glattke, Barbara K. Cone

Research output: Contribution to journalArticlepeer-review

37 Scopus citations


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 amplitudewere observed in all conditions,with right-earamplitudes 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.

Original languageEnglish (US)
Pages (from-to)1464-1476
Number of pages13
JournalJournal of Speech, Language, and Hearing Research
Issue number5
StatePublished - Oct 1 2011


  • Attention
  • Click-evoked otoacoustic emissions (CEOAEs)
  • Contralateral suppression
  • Efferent system
  • Medial olivocochlear (MOC) reflex
  • Medial olivocochlear bundle (MOCB)

ASJC Scopus subject areas

  • Language and Linguistics
  • Linguistics and Language
  • Speech and Hearing


Dive into the research topics of 'The MOC reflex during active listening to speech'. Together they form a unique fingerprint.

Cite this