OBJECTIVE: To study the relationship of distortion product in cochlea with cochlear activity and hearing. METHOD: Time variances of distortion product of basilar membrane vibration in vitro guineapig cochlea were observed by laser interferometry. RESULT: Within half hour after a cochlea was isolated from a guineapig, distortion product accompanied with two-tone inhibition in cochlea, can be observed. As time passed, distortion product and two-tone inhibition effect disappeared at the same time. After that, the membrane contiune vibrating in response to the sound stimulus, but the vibration amplitude decreased obviously and continued decreasing until it disappeared completely. CONCLUSION Distortion product in cochlea is a symbol of cochlear activity which makes the membrane respond in large amplitude vibration to sound stimulus and exhibit two-tone inhibition. The former makes the hearing highly sensitive to sound stimulus, the later makes the hearing perform information abstract well.
Acoustic Stimulation ; Animals ; Basilar Membrane ; physiology ; Cochlea ; physiology ; Guinea Pigs ; Hearing ; physiology ; Hearing Tests ; Interferometry ; Sound