Holographic Investigation of Stapes Footplate Movements

Time-average holography has been applied to measure movements of the stapes footplate. The investigations were performed on fresh human temporal bone preparations with the stapes unloaded by the cochlear fluid. Using the technique with a phase modulated reference wave, a smaller tilt movement was detected in addition to the piston-like movement at 120 … 125 dB SPL (sound pressure level) and 600 Hz frequency.