MOC efferents reflexively modulate cochlear gain via outer hair cells
Evidence
The central nervous system can control sound coding in the cochlea via medial olivocochlear (MOC) efferents (Guinan 2006 ). MOC efferents act upon outer hair cells, inhibiting the mechanical gain in the cochlea for lowand moderate-intensity sounds (Cooper and Guinan 2006 ) and may be activated involuntarily (i.e., in a reflexive manner) by ipsilateral and/or contralateral sounds (Guinan 2006 ). This suggests that auditory sensitivity and dynamic range could be dynamically and adaptively varying during natural, binaural listening depending on the state of activation of MOC efferents. — Dijk, Pim van, Physiology, Psychoacoustics and…, 1941
Categorization
Category: Causal Relationships
- DEFINE: Defines MOC efferents and their reflexive action on outer hair cells — core anatomy/physiology.
Related
- Medial olivocochlear efferents actively modulate cochlear gain during binaural listening (similarity 0.96)
- Brain efferents can dynamically adjust cochlear gain during listening (similarity 0.93)
- Auditory dynamic range adapts moment-to-moment via reflexive efferent state (similarity 0.86)
- Stronger contralateral sound causes greater efferent inhibition and more linear cochlear response (similarity 0.84)
- MOC efferent activation restores auditory nerve dynamic range in noise (similarity 0.84)
- The efferent reflex may improve speech-in-noise coding by restoring neural dynamic range (similarity 0.83)
- Medial olivocochlear reflex inhibition varies by cochlear location (similarity 0.83)
- The medial olivocochlear reflex inhibits cochlear compression contralaterally in a graded, output-dependent manner (similarity 0.82)
- Hair cells actively amplify cochlear vibration rather than only sensing it (similarity 0.82)
- Medial olivocochlear inhibition is stronger apically and shifted half an octave (similarity 0.82)
- The contralateral efferent reflex inhibits cochlear compression at matched frequencies (similarity 0.81)
- The olivocochlear reflex may unmask speech from noise via dynamic-range restoration (similarity 0.81)
- The modeled efferent effects likely generalize to natural acoustic hearing (similarity 0.81)
- Outer haircells amplify quiet sounds only, while inner haircells respond directly to loud ones. (similarity 0.81)
- Psychoacoustic measures probe efferent function even where OAEs fail (similarity 0.81)