Lopez-Najera Alberto, Lopez-Poveda Enrique A, Meddis Ray
Facultad de Medicina, Universidad de Castilla-La Mancha, C/ Almansa, No. 14, 02006 Albacete, Spain.
J Acoust Soc Am. 2007 Oct;122(4):2124-34. doi: 10.1121/1.2769627.
A number of phenomenological models that simulate the response of the basilar membrane motion can reproduce a range of complex features observed in animal measurements over different sites along its cochlea. The present report shows a detailed analysis of the responses to tones of an improved model based on a dual-resonance nonlinear filter. The improvement consists in adding a third path formed by a linear gain and an all-pass filter. This improvement allows the model to reproduce the gain and phase plateaus observed empirically at frequencies above the best frequency. The middle ear was simulated by using a digital filter based on the empirical impulse response of the chinchilla stapes. The improved algorithm is evaluated against observations of basilar membrane responses to tones at seven different sites along the chinchilla cochlear partition. This is the first time that a whole set of animal observations using the same technique has been available in one species for modeling. The resulting model was able to simulate amplitude and phase responses to tones from basal to apical sites. Linear regression across the optimized parameters for seven different sites was used to generate a complete filterbank.
许多模拟基底膜运动响应的现象学模型能够再现沿耳蜗不同部位在动物测量中观察到的一系列复杂特征。本报告展示了对基于双共振非线性滤波器的改进模型对音调响应的详细分析。改进之处在于增加了一条由线性增益和全通滤波器构成的第三条路径。这一改进使该模型能够再现经验观察到的在最佳频率以上频率处的增益和相位平台。通过使用基于灰鼠镫骨经验脉冲响应的数字滤波器来模拟中耳。针对沿灰鼠耳蜗隔板七个不同部位对基底膜对音调的响应观察结果，对改进算法进行了评估。这是首次在一个物种中获得使用相同技术的一整套动物观察结果用于建模。所得模型能够模拟从基底部位到顶端部位对音调的幅度和相位响应。对七个不同部位的优化参数进行线性回归以生成完整的滤波器组。
