Brain efferents can dynamically adjust cochlear gain during listening

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…, 1939

Categorization

Category: Causal Relationships

• DEFINE: Defines MOC efferents and their reflexive activation, core terminology for the chapter.

Related

• Medial olivocochlear efferents actively modulate cochlear gain during binaural listening (similarity 0.96)
• MOC efferents reflexively modulate cochlear gain via outer hair cells (similarity 0.93)
• Auditory dynamic range adapts moment-to-moment via reflexive efferent state (similarity 0.87)
• The modeled efferent effects likely generalize to natural acoustic hearing (similarity 0.86)
• Stronger contralateral sound causes greater efferent inhibition and more linear cochlear response (similarity 0.85)
• Efferent cochlear gain reduction is frequency-selective around the signal frequency. (similarity 0.84)
• MOC efferent activation restores auditory nerve dynamic range in noise (similarity 0.84)
• Signal durations under the efferent onset delay isolate the efferent effect on cochlear gain (similarity 0.84)
• Psychoacoustic measures probe efferent function even where OAEs fail (similarity 0.83)
• The medial olivocochlear reflex inhibits cochlear compression contralaterally in a graded, output-dependent manner (similarity 0.83)
• The contralateral efferent reflex inhibits cochlear compression at matched frequencies (similarity 0.83)
• Medial olivocochlear efferent feedback reduces cochlear gain most for frequencies near the signal (similarity 0.83)
• Contralateral efferent inhibition amplifies interaural level differences (similarity 0.83)
• The efferent reflex may improve speech-in-noise coding by restoring neural dynamic range (similarity 0.83)
• Brainstem efferent signals shorten the hearing Bounce (similarity 0.83)

Broader Connections

• Signal durations under the efferent onset delay isolate the efferent effect on cochlear gain #corroborates (0.85) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5953
• Brainstem efferent signals shorten the hearing Bounce #exemplifies (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3703
• Cochlear gain control lags stimulus envelope changes by a fixed ~50 μs delay #expands (0.80) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3650
• Efferent cochlear gain reduction is greatest when the precursor matches the signal frequency #expands (0.78) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5951
• The cochlea may regulate gain slowly rather than compress sound instantly #responds-to (0.75) — Dijk, Pim van, Physiology, Psychoacoustics and…, 3629
• Otoacoustic and psychophysical estimates of efferent gain disagree due to stimulus constraints #complicates (0.72) — Dijk, Pim van, Physiology, Psychoacoustics and…, 5981