A Study of the Vibration of the Basilar Membrane in Human Temporal Bone Preparations by the Use of the Mossbauer Effect

Using the Mössbauer technique, we have studied the vibration of the human basilar membrane and malleus head in the sound frequency range 0.2--9.0 kHz and at a sound pressure of 100 dB at the tympanic membrane. The displacement frequency response curves for the basilar membrane and the malleus head have similar shapes, with a maximum at about 1 kHz. Below and above 1 kHz the curves have a slope of about 10 dB/octave and--100 dB/octave, respectively. In addition, the basilar membrane has a maximum displacement at a frequency dependent distance from the stapes. A simple hydrodynamic model for the cochlea is used to interpret the experimental data. A possible mechanism for the frequency resolution of sound by the ear and noise-induced hearing loss is discussed.