Comparing methods of modeling near field fluid coupling in the cochlea
Comparing methods of modeling near field fluid coupling in the cochlea
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DOI：
10.1121/1.4908242
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发表时间：
2015-03-01
影响因子：
2.4
通讯作者：
Elliott, Stephen J.
中科院分区：
文献类型：
--
作者：
Ni, Guangjian;Elliott, Stephen J.
除了产生远场压力，使声波在耳蜗内传播外，基底膜（BM）单个元件的振动也会产生近场压力，从而增加其质量并引起局部纵向耦合。本文比较了几种不同的近场压力分布计算方法的效率和精度，并探讨了它们之间的联系。特别指出，在空间域中，对近场压力的波数描述的一般近似等价于远离激发点的指数衰减。近场压力的两个重要性质是其最大振幅（如果振动单元长度有限，则振幅有限）和其空间积分值（决定了流体加载对基底的附加质量）。这些特性是作为BM宽度相对于流体室宽度的函数来计算的。通过以这种方式参数化近场压力变化，可以很容易地将其纳入耳蜗的耦合模型，而无需计算完整的三维压力场的可观计算费用。(C) 2015年美国声学学会。
As well as generating the far field pressure, which allows wave propagation in the cochlea, the vibration of an individual element of the basilar membrane (BM) will also generate a near field pressure, which increases its mass and gives rise to local longitudinal coupling. This paper compares the efficiency and accuracy of a number of different methods of calculating the near field pressure distribution, and explores the connections between them. In particular it is shown that a common approximation to the wavenumber description of the near field pressure is equivalent, in the spatial domain, to an exponential decay away from the point of excitation. Two important properties of the near field pressure are its maximum amplitude, which is finite if the vibrating element has a finite length, and the value of its spatial integral, which determines the added mass on the BM due to the fluid loading. These properties are calculated as a function of the BM width relative to the width of the fluid chamber. By parameterizing the near field pressure variation in this way, it can be readily incorporated into coupled models of the cochlea, without the considerable computational expense of calculating the full three dimensional pressure field. (C) 2015 Acoustical Society of America.