【正文】 2020 屆本科生畢業(yè)設(shè)計(jì) 題目： 基于 matlab 聲音信號(hào)的濾波去噪處理 作 者 姓 名： 柯運(yùn)生 學(xué) 號(hào)： 2020080313 院 （系）： 機(jī)械與電子工程學(xué)院 專(zhuān) 業(yè)： 電子信息工程 指 導(dǎo) 教 師： 邵 毅 蔣明曦 指導(dǎo)教師職稱(chēng)： 講 師 工程師 2020 年 4 月 8 日 SuZhou College Year 2020 Bachelor Graduation Design Title:Based on Matlab Voice Signal Filtering Denoising Processing Author: Ke Yunsheng Student ID: 2020080313 Department: Collage of Mechanical and Electronic Engineering Major: Electronic and Information Engineering Instructor: Shao Yi Jiang Mingxi Professional Title: Lecture Engineer April 8th, 2020 摘 要 在數(shù)字信號(hào)處理中 ,濾波器的設(shè)計(jì)占有極其重要的地位。而其中， FIR 數(shù)字濾波器和 IIR 數(shù)字濾波器是重要組成部分。 Matlab 具有功能強(qiáng)大、簡(jiǎn)單易學(xué)、編程效率高等特點(diǎn) ,深受廣大科技工作者的喜愛(ài)。特別是 Matlab 中還具有信號(hào)分析工具箱 ,所以對(duì)于使用者，不需要具備很強(qiáng)的編程能力 ,就可以方便地進(jìn)行信號(hào)分析、處理和設(shè)計(jì)。利用 Matlab 中的信號(hào)處理工具箱，可以快速有效的設(shè)計(jì)各種數(shù)字濾波器。本論文基于 Matlab 語(yǔ)音信號(hào)處理的設(shè)計(jì)與實(shí)現(xiàn)，綜合運(yùn)用數(shù)字信號(hào)處理的相關(guān)理論知識(shí)，對(duì)加噪聲語(yǔ)音信號(hào)進(jìn)行 時(shí)域、頻域分析并濾波。而后通過(guò)理論推導(dǎo)得出相應(yīng)結(jié)論，再利用 Matlab 作為編程工具進(jìn)行計(jì)算機(jī)實(shí)現(xiàn)工作。在設(shè)計(jì)實(shí)現(xiàn)的過(guò)程之中，使用巴特沃斯、切比雪夫和雙線(xiàn)性變法設(shè)計(jì) IIR 數(shù)字濾波器，使用窗函數(shù)法來(lái)設(shè)計(jì) FIR 數(shù)字濾波器，并利用 Matlab 作為輔助工具，完成設(shè)計(jì)中的計(jì)算與圖形的繪制。通過(guò)對(duì)所設(shè)計(jì)濾波器的仿真和頻率特性的分析可知，利用 Matlab 信號(hào)處理工具箱，可以快捷有效地設(shè)計(jì) FIR和 IIR 數(shù)字濾波器，過(guò)程簡(jiǎn)單、方便，結(jié)果的各項(xiàng)性能指標(biāo)也均達(dá)到指定要求。 關(guān)鍵字 ： Matlab；濾波器； IIR； FIR ABSTRACT In digital signal processing, filter design occupies an extremely important position. And among them, the FIR digital filter and IIR digital filter is an important part. Matlab has powerful function, easy to learn, programming efficiency higher characteristic, and was deeply loved by the masses of scientific and technical also has signal analysis toolbox in Matlab, so for users, don39。t need to have strong programming ability, can be easily signal analysis, processing and design. Signal processing toolbox of Matlab, can be used to quickly and efficiently design all kinds of digital filter. In this paper the design and implementation of speech signal processing based on Matlab, the integrated use of the relevant theoretical knowledge of digital signal processing, to add noise speech signal in time domain, frequency domain analysis and filtering. And then corresponding conclusion through theoretical derivation, using Matlab as a programming tool for puter implementation work. Implementation in the design process, using butterworth, chebyshev and bilinear reform IIR digital filter design, window function method used to design FIR digital filter, and by using the Matlab as an auxiliary tool, to plete the design of puting and graphics drawing. Through a simulation of the designed filter and frequency characteristic analysis shows that using the Matlab signal processing toolbox, can quickly and effectively to design FIR and IIR digital filter, the process is simple, convenient, and the results of various performance indicators meet the specified requirements. Keywords： Matlab。 Filter。 IIR。 FIR 目 錄 緒論 .................................................................................................................1 1 語(yǔ)音信號(hào)處理的基本知識(shí) ................................................................................3 語(yǔ)音的錄入和打開(kāi) ................................................ 3 采樣位數(shù)和采樣頻率 .............................................. 3 時(shí)域信號(hào) FFT 分析 ................................................ 3 數(shù)字濾波器設(shè)計(jì)原理 .............................................. 4 2 Matlab 相關(guān)函數(shù) ............................................................................................5 wavread 函數(shù) .................................................... 5 其他相關(guān)函數(shù) .................................................... 5 3 去噪和仿真的研究 ..........................................................................................7 語(yǔ) 音文件在 Matlab 平臺(tái)上的錄入與打開(kāi) ............................ 7 原始語(yǔ)音信號(hào)頻譜分析及仿真 ..................................... 7 加噪語(yǔ)音信號(hào)頻譜分析及仿真 ..................................... 9 去噪及仿真 .................................................... 11 結(jié)合去噪后的頻譜圖對(duì)比兩種方式濾波的優(yōu)缺點(diǎn) .................... 16 結(jié)論 ...................................................................