Reply to "on cochlear impedances and the miscomputation of power gain" by Shera et al. J. Assoc. Re. Otolaryngol.

Research output: Contribution to journalReview article


Using a scanning laser interferometer, we recently measured the volume velocity of the basilar membrane vibration in the sensitive gerbil cochlea and estimated that the cochlear power gain is ̃100 at low sound pressure levels (Ren et al., Nat Commun 2:216-223, 2011a). We thank Shera et al. for recognizing the technical challenges of our experiments and appreciating the beauty of our data in their comment (Shera et al., J Assoc Res Otolaryngol (in press), 2011). These authors argue that our analysis is inappropriate, invalidating our conclusion; moreover, they suggest that our finding of a power gain of >1 could arise from a passive structure or cochlea. While our analysis and interpretation remain to be verified, they are justified according to commonly accepted assumptions and theories in cochlear mechanics. Here, we also show that the mathematical demonstration of a power gain of >1 in a passive cochlea by Shera et al. is inconsistent with our data, which show that the volume velocity and power gain decrease and become <1 as the sound level increases.

Original languageEnglish (US)
Pages (from-to)677-680
Number of pages4
JournalJARO - Journal of the Association for Research in Otolaryngology
Issue number6
StatePublished - Dec 1 2011



  • Basilar membrane vibration
  • Cochlea
  • Cochler amplifier
  • Laser interferometer
  • Traveling wave

ASJC Scopus subject areas

  • Otorhinolaryngology
  • Sensory Systems

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