HISTOLOGICAL-EVALUATION OF DAMAGE IN CAT COCHLEAS USED FOR MEASUREMENT OF BASILAR-MEMBRANE MECHANICS

Cochleas utilized in basilar membrane vibration measurements were examined histologically using an epon-embedded surface preparation technique. The amount of damage observed at both the apical and basal ends of the cochleas was variable. The apical damage was probably caused by large, low-frequency movements of the basilar membrane. The basal damage was due to trauma produced directly by the surgical and experimental procedure. The sharpness of tuning observed in the basilar membrane frequency response was found to be inversely related to the extent of histological damage.