TY - JOUR
T1 - Fast reverse propagation of sound in the living cochlea
AU - He, Wenxuan
AU - Fhdberger, Anders
AU - Porsov, Edward
AU - Ren, Tianying
N1 - Funding Information:
This project was supported by the National Institutes of Health (grant No. R01 DC004554), the Guanghua Foundation, the Swedish Research Council, the Tysta Skolan Foundation, and Hörselskadades Riksförbund.
PY - 2010/6/2
Y1 - 2010/6/2
N2 - The auditory sensory organ, the cochlea, not only detects but also generates sounds. Such sounds, otoacoustic emissions, are widely used for diagnosis of hearing disorders and to estimate cochlear nonlinearity. However, the fundamental question of how the otoacoustic emission exits the cochlea remains unanswered. In this study, emissions were provoked by two tones with a constant frequency ratio, and measured as vibrations at the basilar membrane and at the stapes, and as sound pressure in the ear canal. The propagation direction and delay of the emission were determined by measuring the phase difference between basilar membrane and stapes vibrations. These measurements show that cochlea-generated sound arrives at the stapes earlier than at the measured basilar membrane location. Data also show that basilar membrane vibration at the emission frequency is similar to that evoked by external tones. These results conflict with the backward-traveling-wave theory and suggest that at low and intermediate sound levels, the emission exits the cochlea predominantly through the cochlear fluids.
AB - The auditory sensory organ, the cochlea, not only detects but also generates sounds. Such sounds, otoacoustic emissions, are widely used for diagnosis of hearing disorders and to estimate cochlear nonlinearity. However, the fundamental question of how the otoacoustic emission exits the cochlea remains unanswered. In this study, emissions were provoked by two tones with a constant frequency ratio, and measured as vibrations at the basilar membrane and at the stapes, and as sound pressure in the ear canal. The propagation direction and delay of the emission were determined by measuring the phase difference between basilar membrane and stapes vibrations. These measurements show that cochlea-generated sound arrives at the stapes earlier than at the measured basilar membrane location. Data also show that basilar membrane vibration at the emission frequency is similar to that evoked by external tones. These results conflict with the backward-traveling-wave theory and suggest that at low and intermediate sound levels, the emission exits the cochlea predominantly through the cochlear fluids.
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U2 - 10.1016/j.bpj.2010.03.003
DO - 10.1016/j.bpj.2010.03.003
M3 - Article
C2 - 20513393
AN - SCOPUS:77952976813
SN - 0006-3495
VL - 98
SP - 2497
EP - 2505
JO - Biophysical Journal
JF - Biophysical Journal
IS - 11
ER -