基于减谱法的语音增强方法的实现

I摘要摘要：在我们的日常交流和语音通信系统中，加性宽带噪声严重影响了语音质量和可懂度。从带噪语音中提取原始语音信号的方法很多，在单信道条件下，减谱算法以其运算量小、原理简单、易于实现并且有不错的增强效果而得到了广泛的应用。减谱语音增强算法的核心是噪声检测和减谱规则。在分析了语音增强算法理论的基础上，本文首先研究了语音激活检测算法。对基于短时能量和短时过零率双门限法语音激活检测的噪声估计算法做了研究及仿真，同时还研究了一种基于最小子带能量的噪声估计方法。然后，通过分析经典减谱法的原理及其一般改进形式，研究了一种基于噪声残差的谱相减改进算法和一种可以不以噪声是零均值的高斯分布为前提的减谱法改进算法。最后通过大量的仿真实验，验证了所研究的几种改进算法都能有效地提高增强效果。关键词：减谱法；语音增强；语音激活检测；噪声估计IIABSTRACTABSTRACT:Inourdailyconversationandspeechcommunicationsystem,theadditivebroadbandnoisehasbadlyimpactonthequalificationandtheintelligibilityofthespeech.Therearemanymethodstopick-upthepurespeechsignalfromnoisyspeechsignal.Undertheconditionofsinglechannel,spectralsubtractionspeechenhancementalgorithmhasbeenwidelyusedbecauseithasmanyadvantages，suchasthecalculationissmall,thetheoryissimple,andtheimplementiseasy.Themainideaofthespectralsubtractionalgorithmisnoisedetectionandspectralsubtractionrule.Firstly,voiceactivitydetectionalgorithmisdiscussedinthispaper.Weresearchandsimulatethevoiceactivitydetectionbasedonshort-timeenergyandshort-timezerocrossingrateandresearchanoiseestimatemethodbasedonminimumsubbandenergy.Then,afteranalyzingtheconventionalspectralsubtractionalgorithmanditsimprovedform,westudytheimprovedspectralsubtractionalgorithmbasedonnoiseresidualerrorandresearchanotherimprovedspectralsubtractionalgorithmwithoutGaussnoise.Finally,manyexperimentalresultsshowthatalltheseimprovedalgorithmscanimprovethequalityofthespeecheffectively.Keywords:spectralsubtraction;speechenhancement;voiceactivitydetection;noiseestimationIII目录摘要....................................................................................................IABSTRACT..............................................................................................II第1章绪论.......................................................................................11.1课题的研究背景..........................................................................................11.2语音增强技术发展现状况..........................................................................21.3本文结构安排..............................................................................................4第2章语音增强算法基础理论...........................................................52.1人耳感知特性..............................................................................................52.2语音产生及其特性分析..............................................................................52.2.1语音信号的声学基础和产生模型...................................................52.2.2语音特性分析...................................................................................62.3噪声分类及其特性......................................................................................72.4语音信号的短时处理..................................................................................82.5语音增强性能..............................................................................................82.6本章小结....................................................................................................10第3章语音激活检测..........................................................................113.1引言............................................................................................................113.2基于短时能量和短时过零率的语音激活检测算法................................123.2.1短时能量.........................................................................................123.2.2短时过零率.....................................................................................133.2.3短时能量和短时过零率双门限算法.............................................133.3实验仿真....................................................................................................153.4本章小结....................................................................................................16第4章噪声参数的估计.....................................................................174.1引言............................................................................................................174.2传统减谱法中所使用的噪声参数估计....................................................174.2.1传统减谱法中噪声参数估计的原理.............................................174.2.2传统减谱法中噪声参数估计的步骤.............................................174.2.3传统减谱法中噪声参数估计的缺点.............................................184.3一种改进的背景噪声检测算法................................................................184.3.1算法的数学模型.............................................................................194.3.2算法原理.........................................................................................19IV4.3.3算法的实现流程.............................................................................204.4本章小节....................................................................................................21第5章减谱算法的具体研究.............................................................235.1概述............................................................................................................235.2传统减谱算法............................................................................................235.2.1功率减谱的原理..................................................................