TY - JOUR
T1 - Basilar membrane vibration in the basal turn of the sensitive gerbil cochlea
AU - Ren, Tianying
AU - Nuttall, Alfred L.
N1 - Funding Information:
Supported in part by research grants from the National Institute of Deafness and Other Communication Disorders (R01 DC000105, PO1 0078 and R03 DC033642), the National Institutes of Health, the Research Fund of the American Otological Society, the Medical Research Foundation of Oregon, and VA RR and D Center Grant RCTR-597-0160, Portland, VAMC.
PY - 2001
Y1 - 2001
N2 - The basal membrane (BM) velocity responses to pure tones were measured using a newly developed laser interferometer microscope that does not require placing a reflecting object on the BM. It was demonstrated that the instrument is able to measure sub-nanometer vibration from the cochlear partition in the basal turn of the gerbil. The overall shape of the amplitude spectra shows typical tuning features. The 'best' frequencies (BFs) for the BM locations studied were between 14 kHz and 27 kHz, depending on the longitudinal position. For a given BM location, tuning sharpness was input level dependent, indicated by the Q(10dB), which varied from approximately 3 at low stimulus levels to near 1.5 at high input levels. At frequencies below BF, parallel amplitude/frequency curves across stimulus levels indicate a linear growth function. However, at frequencies near BF, the velocity increased linearly at low levels (<40 dB SPL) and became compressed between 40 and 50 dB SPL. Although the velocity gain for the frequency range below BF was a function of frequency, for a given frequency the gains were approximately constant across different levels. At frequencies near BF, the velocity gain at low sound pressure level was greater than that at a high sound pressure level, indicating a nonlinear negative relationship to stimulus level. The data also showed that the BF shifts toward the low frequencies with stimulus intensity increase. The phase spectra showed two important features: (1) at frequencies about half octave below the BF, phase slope is very small, indicating an extremely short delay; (2) the greatest phase lag occurs at frequencies near the BF, indicating a significant delay near this frequency range. Copyright (C) 2001 Elsevier Science B.V.
AB - The basal membrane (BM) velocity responses to pure tones were measured using a newly developed laser interferometer microscope that does not require placing a reflecting object on the BM. It was demonstrated that the instrument is able to measure sub-nanometer vibration from the cochlear partition in the basal turn of the gerbil. The overall shape of the amplitude spectra shows typical tuning features. The 'best' frequencies (BFs) for the BM locations studied were between 14 kHz and 27 kHz, depending on the longitudinal position. For a given BM location, tuning sharpness was input level dependent, indicated by the Q(10dB), which varied from approximately 3 at low stimulus levels to near 1.5 at high input levels. At frequencies below BF, parallel amplitude/frequency curves across stimulus levels indicate a linear growth function. However, at frequencies near BF, the velocity increased linearly at low levels (<40 dB SPL) and became compressed between 40 and 50 dB SPL. Although the velocity gain for the frequency range below BF was a function of frequency, for a given frequency the gains were approximately constant across different levels. At frequencies near BF, the velocity gain at low sound pressure level was greater than that at a high sound pressure level, indicating a nonlinear negative relationship to stimulus level. The data also showed that the BF shifts toward the low frequencies with stimulus intensity increase. The phase spectra showed two important features: (1) at frequencies about half octave below the BF, phase slope is very small, indicating an extremely short delay; (2) the greatest phase lag occurs at frequencies near the BF, indicating a significant delay near this frequency range. Copyright (C) 2001 Elsevier Science B.V.
KW - Basilar membrane
KW - Cochlea
KW - Gerbil
KW - Laser interferometer
KW - Vibration
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U2 - 10.1016/S0378-5955(00)00211-2
DO - 10.1016/S0378-5955(00)00211-2
M3 - Article
C2 - 11124451
AN - SCOPUS:0035214972
SN - 0378-5955
VL - 151
SP - 48
EP - 60
JO - Hearing Research
JF - Hearing Research
IS - 1-2
ER -