利用MATLAB软件对音频信号进行频谱分析与处理

毕业设计说明书(论文)利用MATLAB软件对音频信号进行频谱分析与处理毕业设计说明书（论文）中文摘要详细了解了数字滤波器的滤波器设计，比较了FIR和IIR滤波器的不同性能，最终选择了设计IIR滤波器。通过设计低通、高通、带通和带阻等各种滤波器，并分析了各滤波器的幅度特性和相频特性，熟悉了四种滤波器的性能。利用MATLAB软件分析音频信号的幅度响应和相位响应，学习了数字音频信号输入MATLAB环境并通过MATLAB播放的方法。通过比较音频信号输入前与输入后幅度响应和相位响应的差异，验证了以前所学习的转业知识。学习了MATLAB程序设计语言，编写了相应程序，产生了一个可以使操作更加方便的操作界面。画了软件实现和界面操作的流程图。关键词音频信号幅度响应相位响应MATLAB滤波器IIRFIR本科毕业设计说明书（论文）第I页共I页毕业设计说明书（论文）外文摘要TitleToAnalyzeandDisposeTheSpectraofTheAudioSignalWithMATLABAbstractTocomprehendthedesignofdigitalfilterindetail,tocomparetheperformanceoftheFIRfilterandIIRfilter,andfinallytheIIRfilterisbeenchosentodesign.Theamplitudeandphasecharacteristicofthefilterisbeenanalyzed,alsotheperformanceofthefourfiltersisbeenknownwell,throughthedesignoflow-passhigh-pass,band-passandBand-eliminationfilters.UsingMATLABtoanalyzetheamplituderesponseandphaseresponseoftheaudiosignal,tolearnhowtoinputtheaudiosignaltotheMATLABandhowtoplaytheaudiosignalthroughMATLAB.Thespecializedsubjectknowledgeisbeencertifiedbycomparingtheamplituderesponseandphaseresponseofthetwoaudiosignals,andoneofthetwosignalsisbeforeinput,theotherisafterinput.TolearnprogramminginMATLABandthecorrespondingprogramisrealized,alsoanoperationinterfaceisbroughttomaketheprocessingmoreconvenient.Alsotheflowchartabouttherealizationofthesoftwareandtheinterfaceprocessingisbeendrown.KeywordsaudiosignalamplituderesponsephaserespondMATLABfilterIIRFIR本科毕业设计说明书（论文）第II页共I页目次1引言····················································································································································11．1研究背景···········································································································································11.2本文主要研究内容··························································································································12MATLAB简介·····································································································································32.1什么是MATLAB···································································································································32.2MATLAB的发展历史·························································································································32.3MATLAB系统·······································································································································42.4MATLAB的主要功能和特性···········································································································63.数字滤波器简介·····························································································································83.1数字滤波器的定义及分类············································································································83.2数字滤波器设计方法···················································································································104.音频信号频谱分析的软件实现··································································································134.1数字滤波器设计······························································································································134.2音频信号频谱分析·······················································································································174.3界面设计··········································································································································37结论····················································································································································43致谢····················································································································································44参考文献·········································································································································45本科毕业设计说明书（论文）第1页共45页1引言1.1研究背景在计算机技术日新月异的今天，计算机已同人们的日常生活和工作越来越紧密的联系在一起。而在工程计算领域中，计算机技术的应用正逐步把科技人员从繁重的计算工作中解放出来。在科学研究和工程应用的过程中，往往需要进行大量的数学计算，传统的纸笔和计算器已根本不能满足海量计算的要求。MATLAB的产生是与数学计算紧密联系在一起的，MATLAB由主包和功能各异的工具箱组成，其基本数据结构是矩阵，它具有非常强大的计算功能，正是凭借其杰出的性能，MATLAB现在已成为世界上应用最广泛的工程计算应用软件之一。MATLAB在国外的高校已成为大学生、硕士生、博士生必须掌握的基本程序设计语言。信号处理是科学研究和工程技术许多领域都需要进行的一个重要环节，这种处理包括信号的检测、变换、滤波、传输、信号提取等。传统上对信号的处理大都采用模拟系统来实现，然而，随着人们对信号处理要求的不断提高，以及模拟信号处理中一些不可克服的缺点，对信号的许多处理转而采用数字的方法来进行。信号处理技术是开发具有自主知识产权的各类先进产品的瓶颈，是一项关键技术。MATLAB是一种面向科学与工程计算的高级语言，已成为数学、信息、控制、经济等诸多学科实用的仿真软件。MATLAB是一套用于科学计算的可视化高性能语言与软件环境。它集数值分析、矩阵运算、信号处理和图形显示与一体，构成了一个界面友好的用户环境。信号处理是MATLAB应用最成功的领域之一，MATLAB将信号处理中的许多常用算法编写成了可调用的函数，汇集构成了信号处理工具箱。它的信号处理工具箱包含了各种经典的和现代的数字信号处理技术，是一个非常优秀的算法研究与辅助设计的工具。1.2本文主要研究内容MATLAB具有非常强大的计算功能，凭借其杰出的性能，MATLAB现在已经成为世界上应用最广泛的工程计算应用软件之一。MATLAB已经是理工科的学生必须掌握的应用软件了。本文利用MATLAB处理音频信号，掌握了MATLAB的使用方法，详细了解了MATLAB的产生发展过程及原理。分析了三种音频信号的频谱，运用MATLAB设计了低通、高通、带通、带阻等四种IIR数字滤波器，并分析了这三种音频信号通过四种不同滤波器后的频谱，比较了前后频谱的不同。设计IIR数字滤波器的方法不尽相同，本科毕业设计说明书（论文）第2页共45页带通滤波器和带阻滤波器采用的是巴特沃思滤波器，低通滤波器采用的是椭圆滤波器，而高通滤波器采用的是切比雪夫II滤波器。为了操作简便，特地在任务之外又设计了一个操作界面，这样就使得运行MATLAB程序变得更加简便了。本科毕业设计说