Hearing / BM vibration / Active process
Active process
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basilar membrane vibration patterns recorded from intact cochleae in alive animals are much more narrow (frequency selective) and have much lower thresholds than the passive responses observed von Bekesy
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this enhanced frequency selectivity is due to an ACTIVE MECHANICAL PROCESS that amplifies the basilar membrane movement, and increases the sharpness of tuning
- after years of intense investigation, it was determined that the contractile properties of the outer hair cells are the source of the amplification