Normal cochlear basilar membrane vibration elicited with sound stimuli in guinea pigs

Laser Doppler velocimeter was used to determine the amplitude and the velocity of cochlear BM vibration in 18 normal hearing guinea pigs. The input-output (I/O) functional curve and the frequency transfer function of BM vibration were analyzed. The results indicate that the BM vibration of normal guinea pigs elicited with tone burst is a sinusoid whose frequency is the same as the sound frequency stimulated. I/O function of BM vibration displays a nonlinear char acteristics at BF. The frequency transfer function shows that the BM vibration model tallies with the traveling wave theory when delivered with a strong sound and accords with the resonance theory when delivered with weak sound.