非线性离散时间耳蜗力学建模、Volterra泛函分析及在语声处理中的应用

Nonlinear Discrete-Time Cochlear Mechanics:Modelling and Its Volterra Functional Analysis with Applications to Speech Signal Processing

由于数字语音通信等方面发展的需要,对语音信号处理的研究日益深入,研究听觉系统处理语音信息的机理显得越来越重要。本文首先建立了耳蜗力学的非线性运动方程及其离散时/空域状态空间方程;然后根据Volterra泛函级数和非线性传递函数理论,提出了分析耳蜗力学非线性运动方程解的新方法,该方法可以求得耳蜗力学模型满足任意精度的频域解析解,它为耳蜗运动机理的研究提供了一种新的理论与方法;最后,本文将所建立的耳蜗力学模型应用于语音分析/综合系统中,模拟结果表明重建语音质量令人满意,证明了本文模型的正确性和可行性。

Because of the demand for the development of digital speech communication etc., the investigation into the speech signal processing is going in depth, and it is more important to study the mechanism of auditory signal processing. In this paper, the nonlinear motion equation and the corresponding discrete time/discrete space state equation of the cochlea are established firstly. Based on Volterra series and nonlinear transfer function theories, a new approach to analyze the nonlinear properties of the cochlea is promoted secondly, the analytic solution in frequency domain which may be arbitrarily closed to the accurate one can be obtained with the approach, which provides with a new kind of theory and methodology for deeply investigating the mechanism of the cochlea. Finally, the proposed cochlear mechanics model is applied to a speech analysis/synthesis system, the simulation results with satisfactory synthesized speech quality demonstrate the accuracy and effectness of this proposed modelling.