Computational Neuroscience and Cluster of Excellence "Hearing4all," Department for Neuroscience, University of Oldenburg, Oldenburg, Germany
Google Inc., 1600 Amphitheatre Parkway, Mountain View, California 94043, USA
J Acoust Soc Am. 2018 May;143(5):EL418. doi: 10.1121/1.5038595.
The cascade of asymmetric resonators with fast-acting compression (CARFAC) is a cascade filterbank model that performed well in a comparative study of cochlear models, but exhibited two anomalies in its frequency response and excitation pattern. It is shown here that the underlying reason is CARFAC's inclusion of quadratic distortion, which generates DC and low-frequency components that in a real cochlea would be canceled by reflections at the helicotrema, but since cascade filterbanks lack the reflection mechanism, these low-frequency components cause the observed anomalies. The simulations demonstrate that the anomalies disappear when the model's quadratic distortion parameter is zeroed, while other successful features of the model remain intact.
具有快速压缩作用的非对称谐振器级联 (CARFAC) 是一种级联滤波器组模型，在对耳蜗模型的比较研究中表现出色，但在其频率响应和激励模式中表现出两个异常。本文表明，其根本原因是 CARFAC 包含二次失真，这会产生直流和低频分量，在真实的耳蜗中，这些分量会被螺旋体的反射抵消，但由于级联滤波器组缺乏反射机制，这些低频分量导致了观察到的异常。模拟表明，当模型的二次失真参数为零时，异常现象消失，而模型的其他成功特征保持不变。
