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 IIR FIR 本科毕业设计说明书（论文）

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毕业设计说明书（论文）外文摘要

Title To Analyze and Dispose The Spectra of The Audio Signal With MATLAB Abstract To comprehend the design of digital filter in detail, to compare the performance of the FIR filter and IIR filter, and finally the IIR filter is been chosen to design. The amplitude and phase characteristic of the filter is been analyzed, also the performance of the four filters is been known well, through the design of low-pass high-pass, band-pass and Band-elimination filters. Using MATLAB to analyze the amplitude response and phase response of the audio signal, to learn how to input the audio signal to the MATLAB and how to play the audio signal through MATLAB. The specialized subject knowledge is been certified by comparing the amplitude response and phase response of the two audio signals, and one of the two signals is before input, the other is after input. To learn programming in MATLAB and the corresponding program is realized, also an operation interface is brought to make the processing more convenient .Also the flow chart about the realization of the software and the interface processing is been drown. Keywords audio signal amplitude response phase respond MATLAB filter IIR FIR

本科毕业设计说明书（论文）

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目 次

1 引言 ···················································································································································· 1 1．1 研究背景 ··········································································································································· 1 1.2 本文主要研究内容 ·························································································································· 1 2 MATLAB简介 ····································································································································· 3 2.1 什么是MATLAB ··································································································································· 3 2.2 MATLAB的发展历史 ························································································································· 3 2.3 MATLAB系统 ······································································································································· 4 2.4 MATLAB的主要功能和特性 ··········································································································· 6 3. 数字滤波器简介 ····························································································································· 8 3.1 数字滤波器的定义及分类 ············································································································ 8 3.2 数字滤波器设计方法··················································································································· 10 4.音频信号频谱分析的软件实现 ·································································································· 13 4.1 数字滤波器设计 ······························································································································ 13 4.2 音频信号频谱分析 ······················································································································· 17 4.3 界面设计 ·········································································································································· 37 结 论 ···················································································································································· 43 致 谢 ···················································································································································· 44 参 考 文 献 ········································································································································· 45