豚鼠耳蜗基底膜的振动特性

Vibration Characteristics of Cochlear Basilar Membrane in Guinea Pig

为探讨豚鼠耳蜗基底膜的听觉机制,利用多普勒激光测振技术进行了声音在28只成年健康豚鼠耳中传递的测试实验.将豚鼠麻醉后切断头取出听泡,采用电钻暴露其耳蜗基底膜,利用多普勒激光测振仪在给定的声压级、频率的纯音激励条件下测量豚鼠外耳道耳蜗基底膜的振动速度,并测量了中耳镫骨的振动速度.结果表明,豚鼠外耳道基底膜具有频率选择特性,而且其基底膜的振动具有行波特性.

In order to study the auditory mechanism of the guniea pig cochlea,the stapes footplate（SF）and basilar membrane（BM）velocity responses to pure tone were measured using a laser Doppler velocimetry which was able to measure sub-nanometer vibration from the middle ear and cochlea of the guinea pig.The BM velocity was measured by a reflective microbeads placed onto the scala tympani surface of the BM.The velocity response of the SF was also tested,allowing the calculation of a BM transfer function.The transfer function shows typical tuning features.For a given BM location,the characteristic frequency（CF）of the BM was about 11 kHz.The results show that frequency selectivity and travelling wave exist in the BM.