基于改进小波阈值函数的语音增强算法研究  

A Speech Enhancement Algorithm Based on Improved Wavelet Threshold Function

作　　者：覃爱娜[1] 戴亮[1] 李飞[1] 曹卫华[1] 

机构地区：[1]中南大学信息科学与工程学院,湖南长沙410083

出　　处：《湖南大学学报（自然科学版）》2015年第4期136-140,共5页Journal of Hunan University:Natural Sciences

基　　金：国家自然科学基金资助项目(61202340)~~

摘　　要：针对传统的小波阈值去噪算法中的阈值函数不足,提出一种优于非负死区阈值函数的改进的阈值函数.改进阈值函数不仅具有良好的连续性、可导性,并且克服了非负死区阈值函数没有考虑小波变换模值的衰减符合指数规律这一特点.另外在阈值的选取中,考虑了带噪语音信号的不同特性,采用谱平坦度函数修正阈值.仿真实验表明,与传统的非负死区阈值函数去噪算法相比,改进的阈值函数能更有效地消除背景噪声,在提高输出信噪比的同时,更好地保持语音质量和清晰度.To address the limitations of the traditional wavelet threshold denoising function, an im- proved wavelet threshold function was proposed. The improved threshold function not only has good conti- nuity but also overcomes the lack of the non-negative dead zone threshold function and considers the char- acteristic of the attenuation of the noise wavelet modulus values. In addition, the use of spectral flatness function corrects the threshold values adaptively. The simulation results have showed that the improved wavelet threshold can eliminate ground noise effectively, maintain higher speech quality and definition while improving the signal to noise ratio （SNR） of the output.

关 键 词：语音增强 小波变换 阈值去噪 

分 类 号：TN912.3[电子电信—通信与信息系统]