耳蜗结构对低频信号频散特性的影响

发布时间：2018-04-01 04:40

本文选题：耳蜗　切入点：基底膜(BM)　出处：《应用数学和力学》2014年08期

【摘要】：耳蜗是人体最为精密的力学元器件,能处理频率从几十到几万赫兹的声信号.实验研究表明,声波进入耳蜗后,沿着基底膜传播,基底膜能够将不同频率的声信号分散到不同的位置,并为位于基底膜上的毛细胞所感知,就像一个天然的Fourier(傅里叶)滤波器.在von Békésy行波理论框架体系下,基于Manoussaki等的三维螺旋基底膜流固耦合耳蜗模型,考虑耳蜗导管高度和基底膜刚度均为纵向梯度变化,推导出基底膜声波传播的频散方程,分别分析了基底膜刚度和耳蜗导管高度对频散特性的影响.发现耳蜗内淋巴液的存在大大提高了耳蜗对低频信号的处理能力,且捕获频率随基底膜刚度和耳蜗导管高度的减小而降低,两者梯度变化在声信号调制中起协同作用.最后,以人、沙鼠和豚鼠的具体耳蜗参数为例,得到3种生物耳蜗频率-点位图,并验证了低频段模型预测的正确性,比较分析了耳蜗频散功能与生物适应性之间的关系.
[Abstract]:The cochlea is the most sophisticated mechanical component of the human body, capable of processing sound signals with frequencies ranging from tens of thousands of hertz to tens of thousands of hertz.Experimental studies have shown that sound waves travel along the basement membrane after entering the cochlea, and the basement membrane can disperse the sound signals of different frequencies to different locations and be sensed by the hair cells located on the basement membrane.It's like a natural Fourier filter.In the framework of von B 茅 k 茅 sy traveling wave theory, a three-dimensional spiral basilar membrane fluid-solid coupling cochlear model based on Manoussaki et al was developed. Considering the vertical gradient of cochlear duct height and basement membrane stiffness, the dispersion equation of acoustic wave propagation was derived.The effects of basement membrane stiffness and cochlear catheter height on dispersion characteristics were analyzed respectively.It was found that the presence of endolymphatic fluid in the cochlea greatly improved the processing ability of the low frequency signal and the capture frequency decreased with the decrease of the stiffness of the basement membrane and the height of the cochlear catheter. The gradient changes of the two kinds of fluid played a synergistic role in the modulation of acoustic signals.Finally, taking the specific cochlear parameters of human, gerbils and guinea pigs as examples, three kinds of cochlear frequency-spot maps were obtained, and the correctness of the low-frequency model was verified. The relationship between cochlear dispersion function and biological adaptability was compared and analyzed.
【作者单位】：机械结构强度与振动国家重点实验室(西安交通大学);
【基金】：国家自然科学基金(11272242;91016008)~~
【分类号】：R764

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