目的:研究耳蜗畸变产物与基膜调谐功能关系。方法:采用激光干涉技术,对18例刚死亡豚鼠在体耳蜗基膜在频率为1 000Hz和1 400Hz纯音激励下振动的畸变产物及其调谐曲线随时间变化进行测量。结果:观察到耳蜗基膜振动畸变产物幅度随时间变化逐渐衰减,直至消失。与之相伴的是基膜调谐曲线的锐度逐渐钝化,响应幅度逐渐下降。在畸变产物消失后基膜响应幅度极度下降,调谐曲线极度平坦。结论:基膜振动畸变产物与基膜对声激励的响应幅度和调谐锐度有关联,基膜振动畸变产物是否存在,反映了耳蜗中影响听力水平与音调辨识能力的基膜响应幅度增强功能与调谐锐化功能是否存在并发挥作用。
Objective:To explore the relation between distortion products and frequency tuning charateristics in cochlear basilar membrane.Method:Time variances curves of distortion products and frequency tuning curves of basilar membrane response were measured by laser interferometery in situ guinea pig cochlea.Result:Response sensitivity and tuning sharpness of basilar membrane response decreased with distortion product amplitude and become most low and flat when distortion products disappeared.Conclusion:Distortion products in cochlea are related with hearing sensitivity and frequency tuning.They are indicator whether function of cochlear hearing sensitivity enhancing and frequency tuning sharpening is still at work.