正常豚鼠声刺激诱发的耳蜗基底膜振动  

Normal cochlear basilar membrane vibration elicited with sound stimuli in guinea pigs

作　　者：郭梦和[1,2] 任田英[1,2] AlfredL.Nutal 

机构地区：[1]第四军医大学西京医院耳鼻咽喉科 [2]美国波特兰医科大学听力研究中心

出　　处：《第四军医大学学报》1997年第5期454-457,共4页Journal of the Fourth Military Medical University

摘　　要：目的：研究正常听力豚鼠耳蜗基底膜的振动模式．方法：对１８只正常听力豚鼠采用激光多普勒测速仪测定经短纯音和宽带噪声诱发的基底膜振动的振幅、速度，并进行输入－输出函数曲线和频率传递函数分析．结果：短纯音诱发的基底膜振动曲线为正弦曲线．在振动曲线起始部有０．３ｍｓ的无反应期，这是声波从声源传到内耳所需时间．３１ｄＢＳＰＬ短纯音诱发的基底膜振动平均速度为（３４．１２±６．８２）μｍ／ｓ，平均振幅为（０．１２±０．０２）ｎｍ．输入－输出函数曲线在测试点最佳频率（ＢＦ，约１８ｋＨｚ）曲线呈压缩非线性．而在低于最佳频率的曲线呈线性．频率传递函数曲线显示高声强时高于ＢＦ的频率为一个陡峭的斜坡，而在ＢＦ低频侧呈一缓慢的斜坡．这一现象符合行波学说．而低声强时，仅在ＢＦ附近基底膜有反应．这一现象又符合部位共振学说．结论：短纯音诱发的正常豚鼠耳蜗基底膜振动为一与声刺激频率相同的正弦运动．输入－输出函数曲线示正常豚鼠基底膜振动的非线性特性．频率传递函数提示，在高声强刺激时，基底膜振动模式符合行波学说，在低声强刺激时又符合部位共振学说．Objective: This experiment was to investigate cochlear basilar membrane (BM) vibration model in normal hearing guinea pigs. Methods: Laser Doppler velocimeter was used to determine the amplitude and the velocity of cochlear BM vibration in 18 normal hearing guinea pigs. The input output (I/O) functional curve and the frequency transfer function of BM vibration were analyzed. Results: The BM vibration elicited with tone burst was a sinusoid curve. There was no responses at the start of 0.3 ms in the vibrational curve, which was the conductive time of sound from the source of sound to the inner ear. The mean velocity of BM vibration elicited with tone burst 31 dB SPL was (34.12±6.82) μm/s and the mean amplitude was (0.12±0.02) nm. The I/O functional curve at the best frequency (BF) of test point (about 18 kHz) displayed a compressive nonlinear but the curves lower than BF were linear. Frequency transfer function showed that there was a steep slope in the higher frequencies of BF and a slow slope in the lower frequencies of BF, when delivered with strong noise. This phenomenon conforms the traveling wave theory. When weak noise was delivered, the BM responses could only be seen at the BF region, which conforms the resonance theory. Conclusions: The results indicate that the BM vibration of normal guinea pigs elicited with tone burst is a sinusoid whose frequency is the same as the sound frequency stimulated. I/O function of BM vibration displays a nonlinear char acteristics at BF. The frequency transfer function shows that the BM vibration model tallies with the traveling wave theory when delivered with a strong sound and accords with the resonance theory when delivered with weak sound.

关 键 词：耳蜗 基底膜 振动模式 声刺激 

分 类 号：R764.35[医药卫生—耳鼻咽喉科] R339.16[医药卫生—临床医学]