課程設(shè)計基于MATLAB的語音信號分析與處理的課程設(shè)計實驗報告

1、目 錄緒論1正文：一、設(shè)計目的及要求2二、設(shè)計過程2三、調(diào)試分析6四、結(jié)果分析與體會11五、參考文獻(xiàn)12六、謝辭12緒 論數(shù)字信號處理（digital signal processing,dsp）是從20世紀(jì)60年代以來，隨著信息學(xué)科和計算機(jī)學(xué)科的高速發(fā)展而迅速發(fā)展起來的一門新興學(xué)科。它的重要性日益在各個領(lǐng)域的應(yīng)用中表現(xiàn)出來。簡言之，數(shù)字信號處理是把信號用數(shù)字或符號表示的序列，通過計算機(jī)或通用（專用）信號處理設(shè)備，用數(shù)字的數(shù)值計算方法處理（例如濾波、變換、壓縮、增強(qiáng)、估計、識別等），以達(dá)到提取有用信息便于應(yīng)用的目的。數(shù)字信號處理的應(yīng)用包括濾波與變換、通信、語音、語言、圖像、圖形、消費電子、儀器

2、、工業(yè)控制與自動化、醫(yī)療、軍事等。其發(fā)展方向也是多方面的，包括數(shù)字匯聚、遠(yuǎn)程會議系統(tǒng)、融合網(wǎng)絡(luò)、數(shù)字圖書館、圖像與文本合一的信息檢索業(yè)務(wù)、多媒體通信、個人信息終端等。在本次設(shè)計中，就以設(shè)計一個數(shù)字濾波器系統(tǒng)為目的。濾波器按頻率劃分有低通、高通、帶通、帶阻全通等類型。一個數(shù)字濾波器可以用一個系統(tǒng)函數(shù)來表示，若要得到該系統(tǒng)函數(shù)，就要得到以z(-1)升冪排列的傳輸函數(shù)的分子和分母多項式的系數(shù)，即向量num、den，而這兩個參數(shù)由num den=butter(n,wn)、n,wn=buttord(wp,ws,rp,rs)這一函數(shù)得出，這是巴特沃思濾波器的設(shè)計過程。由于頻率響應(yīng)的周期性，頻率變量以數(shù)字頻

3、率來表示，=2*f/fc，f為模擬域頻率，fc為抽樣頻率，所以數(shù)字濾波器設(shè)計中必須給出抽樣頻率。在這次設(shè)計中采用了巴特沃思和切比雪夫兩種濾波器，這兩種濾波器又分別采用了高通、低通、帶通、帶阻四種頻率特性實現(xiàn)，從橫向上和縱向上都可以進(jìn)行對比，表現(xiàn)出各種濾波器的不同特性。 一、設(shè)計目的及要求1課程設(shè)計目的 綜合運用數(shù)字信號處理的理論知識進(jìn)行頻譜分析和濾波器設(shè)計，通過理論推導(dǎo)得出相應(yīng)結(jié)論，再利用 matlab 作為編程工具進(jìn)行計算機(jī)實現(xiàn)，從而加深對所學(xué)知識的理解，建立概念。2課程設(shè)計基本要求 1） 學(xué)會 matlab 的使用，掌握 matlab 的程序設(shè)計方法。 2） 掌握在 windows 環(huán)境下

4、語音信號采集的方法。 3） 掌握數(shù)字信號處理的基本概念、基本理論和基本方法。 4） 掌握 matlab 設(shè)計 fir 和iir 數(shù)字濾波器的方法。 5） 學(xué)會用 matlab 對信號進(jìn)行分析和處理。3課程設(shè)計內(nèi)容錄制一段自己的語音信號，并對錄制的信號進(jìn)行采樣；畫出采樣后語音信號的時域波形和頻譜圖；給定濾波器的性能指標(biāo)，設(shè)計數(shù)字濾波器，并畫出濾波器的頻率響應(yīng)；然后用自己設(shè)計的濾波器對采集的語音信號進(jìn)行濾波，畫出濾波后信號的時域波形和頻譜，并對濾波前后的信號進(jìn)行對比，分析信號的變化；回放語音信號；最后，用 matlab 設(shè)計一信號處理系統(tǒng)界面。二、設(shè)計過程1、 打開gui窗口：file new g

5、ui create new gui blank gui(default) ok2、 控件設(shè)計：在控件布局設(shè)計區(qū)放置四個axes控件、六個push button控件、一個button group控件和兩個radio button控件、四個static text控件。3、 修改控件屬性：選中需要修改屬性的控件，雙擊打開屬性查看器，具體設(shè)置如下：1) 五個axes控件 tag作用axes1提供坐標(biāo)畫出原始信號波形axes2提供坐標(biāo)畫出原始信號頻譜axes3提供坐標(biāo)畫出濾波后信號波形axes4提供坐標(biāo)畫出濾波后信號頻譜axes5提供坐標(biāo)畫出濾波器頻率響應(yīng)2) 六個push button控件：strin

6、gtagstringtag低通pushbutton1帶阻pushbutton4高通pushbutton2原始信號pushbutton5帶通pushbutton3關(guān)閉窗口pushbutton63) 一個button group控件和兩個radio button控件： stringstyletag請選擇濾波器種類button groupuipanel5巴特沃思radio buttonradiobutton1切比雪夫radio buttonradiobutton24) 五個static text控件（這五個static text控件是對坐標(biāo)軸中圖形的說明）：tagstringtext1原始信號波形t

7、ext2原始信號頻譜text3濾波后信號波形text4濾波后信號頻譜text5濾波器頻率響應(yīng)4、 保存：設(shè)置好各個控件的屬性，回到gui主窗口保存，給文件命名為hy，同時hy.m文件打開。5、 設(shè)置回調(diào)函數(shù)：在hy.m文件窗口中設(shè)置回函數(shù)。這里，雖然gui自動生成了回調(diào)函數(shù)，但是回調(diào)函數(shù)是空的，需要在hy.m文件中對它進(jìn)行定義說明。該程序只需要對六個push button控件的回調(diào)函數(shù)進(jìn)行定義說明。六個push button控件的回調(diào)函數(shù)：1）“低通”按鍵的回調(diào)函數(shù)function pushbutton1_callback(hobject, eventdata, handles)y,fs,bi

8、ts=wavread(e:hy.wav); %函數(shù)wavread是對語音信號進(jìn)行 采樣，格式是y,fs,nbit=wavread，返回采樣值放在向量y中，fs表示采樣頻率（hz），nbit表示采樣位數(shù)。fp=1000;fs=2000;rp=0.5;rs=40;fc=40000;%設(shè)定通帶截止頻率（fp）、阻帶截止頻率（fs）、通帶波紋系數(shù)（rp）、阻帶波紋系數(shù)（rs）、抽樣頻率（fc）。wp=2*fp/fc;ws=2*fs/fc; %將模擬域轉(zhuǎn)化成數(shù)字域。if get(handles.radiobutton1,value) %如果選擇radiobutton1，則制做巴特沃思濾波器。n,wc=b

9、uttord(wp,ws,rp,rs); %估算巴特沃思濾波器的階數(shù)n和3db截止頻率wc。num,den=butter(n,wc); %求傳輸函數(shù)的分子和分母多項式的系數(shù)。else %選擇radiobutton2，則制做切比雪夫型濾波器。n,wc=cheb1ord(wp,ws,rp,rs); %估算切比雪夫型濾波器的階數(shù)n和截止頻率wc。num,den=cheby1(n,rp,wc); %求傳輸函數(shù)的分子和分母多項式的系數(shù)。endx=filter(num,den,y); %根據(jù)傳輸函數(shù)的分子和分母多項式的系數(shù)得到模擬濾波器，并將y通過該濾波器，得到x。sound(x,fc,bits); %將

10、濾波后的信號x進(jìn)行回放。x=fft(x); %將x信號進(jìn)行快速傅里葉變換。axes(handles.axes3);plot(x); %在axes3坐標(biāo)軸上畫出x信號的波形圖。axes(handles.axes4);plot(abs(x); %在axes4坐標(biāo)軸上畫出x信號的頻譜圖。h,f=freqz(num,den,256,fc); %求濾波器的頻率響應(yīng)。axes(handles.axes5);plot(f,abs(h),k); %在axes5坐標(biāo)軸上以黑線畫出濾波器的頻率響應(yīng)。2）“高通”按鍵的回調(diào)函數(shù)function pushbutton2_callback(hobject, eventd

11、ata, handles)y,fs,bits=wavread(e:hy.wav);fp=2000;fs=1000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/fc;if get(handles.radiobutton1,value)n,wc=buttord(wp,ws,rp,rs);num,den=butter(n,wc,high); %返回n階高通濾波器。else n,wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(n,rp,wc,high);endx=filter(num,den,y);sound(x,fc,bits);

12、x=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(x);h,f=freqz(num,den,256,fc);axes(handles.axes5);plot(f,abs(h),k);3）“帶通”按鍵的回調(diào)函數(shù)function pushbutton3_callback(hobject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);fp=3000,8000;fs=1000,10000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/f

13、c;if get(handles.radiobutton1,value)n,wc=buttord(wp,ws,rp,rs);num,den=butter(n,wc); %wc為雙元素向量，返回2n階帶通濾波器。else n,wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(n,rp,wc);endx=filter(num,den,y);sound(x,fc,bits);x=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(x);h,f=freqz(num,den,256,fc);axes

14、(handles.axes5);plot(f,abs(h),k);4）“帶阻”按鍵的回調(diào)函數(shù)function pushbutton4_callback(hobject, eventdata, handles)y,fs,bits=wavread(e:hy.wav);fp=1000,10000;fs=3000,8000;rp=0.5;rs=40;fc=40000;wp=2*fp/fc;ws=2*fs/fc;if get(handles.radiobutton1,value)n,wc=buttord(wp,ws,rp,rs);num,den=butter(n,wc,stop); %返回2n階帶阻濾波

15、器。else n,wc=cheb1ord(wp,ws,rp,rs);num,den=cheby1(n,rp,wc,stop);endx=filter(num,den,y);sound(x,fc,bits);x=fft(x);axes(handles.axes3);plot(x);axes(handles.axes4);plot(abs(x);h,f=freqz(num,den,256,fc);axes(handles.axes5);plot(f,abs(h),k);5）“原始信號”按鍵的回調(diào)函數(shù)function pushbutton5_callback(hobject, eventdata,

16、handles)y,fs,bits=wavread(e:hy.wav);sound(y,fs,bits);y=fft(y);axes(handles.axes1);plot(y);axes(handles.axes2);plot(abs(y);6）“關(guān)閉窗口”按鍵的回調(diào)函數(shù)function pushbutton6_callback(hobject, eventdata, handles)close6、 保存修改后的hy.m文件，單擊gui主窗口工具欄中的“激活運行”按鈕，在gui界面中按下“原始信號”按鍵就可以看到原始信號的波形和頻譜，并播放原始信號；選擇濾波器種類（巴特沃思或切比雪夫），然后

17、按下“高通”、“低通”、“帶通”、“帶阻”其中一個按鍵，就可以看到原信號經(jīng)過濾波器后的信號的波形與頻譜，并播放該信號。三、調(diào)試分析圖1 控件布局圖2 單擊“激活運行”后界面圖3 巴特沃思高通濾波器圖4 切比雪夫高通濾波器圖5 巴特沃思低通濾波器圖6 切比雪夫低通濾波器 圖7 巴特沃思帶通濾波器 圖8 切比雪夫帶通濾波器 圖9 巴特沃思帶阻濾波器圖10 切比雪夫帶阻濾波器圖3圖10為巴特沃思和切比雪夫型濾波器在不同頻率特性下產(chǎn)生的信號波形與頻譜，同時有原信號作對比。可以看出，巴特沃思濾波器的頻率特性曲線無論在通帶還是在阻帶內(nèi)，都是頻率的單調(diào)函數(shù)，切比雪夫型濾波器的幅頻特性在通帶內(nèi)是等波紋的，阻帶

18、內(nèi)是單調(diào)的。因為在回調(diào)函數(shù)中，高通和低通、帶通和帶阻濾波器的截止頻率、波紋系數(shù)、抽樣頻率設(shè)定的值是相同的，所以在下圖中縱向?qū)Ρ瓤梢钥闯觯盘柾ㄟ^高通和低通濾波器之后頻譜相對于原信號是互補(bǔ)的，如果對于高通濾波器在某一頻率段上有幅值，那么對于低通濾波器該頻率幅值為零。同理于帶通和帶阻濾波器。橫向上對比可以看出不同濾波器選頻特性也不同，特別是在圖7圖10中選頻邊界處的頻譜處理可以看出，切比雪夫濾波器比巴特沃思濾波器的選頻特性好。四、結(jié)果分析與體會濾波器的作用就是濾除掉阻帶內(nèi)有頻率分量，保留通帶內(nèi)的頻率分量。在圖3圖10的波形圖和頻譜圖中可以看出，經(jīng)過濾波器處理后，不僅濾除掉了原信號的部分頻率分量，原

19、信號的幅度也會有所衰減，而低通和帶阻濾波器產(chǎn)生的信號相對于原信號變化不大，是因為設(shè)定的選頻范圍是原信號的頻率段中較集中的部分，所以與此同時，高通和帶通濾波器產(chǎn)生的信號相對于原信號的幅度就會大大衰減，其原因也是在于高通和帶通濾波器的選頻范圍是原信號頻率范圍中較少的一部分。在信號回放時，低通和帶阻濾波器回放的音頻信號與原信號相比，音色有一點低沉；而高通和帶通濾波器回放的音頻信號，幾乎已經(jīng)聽不到什么聲音，這也說明了這兩種濾波器產(chǎn)生的信號頻率只占原信號頻率范圍中較少的部分。所以根據(jù)各個濾波器的選頻范圍及濾波后信號的音效，可大致判斷原信號的頻率多集中在1000hz以下。通過這次課設(shè)，使我對濾波器有了更深

20、的認(rèn)識，特別是濾波器參數(shù)對濾波器性能的影響，因為通帶截止頻率、阻帶截止頻率、通帶波紋系數(shù)、阻帶波紋系數(shù)都是要影響濾波器的階數(shù)，而濾波器的階數(shù)越大，其選頻特性就越好。因為濾波器處理的音頻信號是我自己的聲音，所以通過濾波器處理后音頻信號的變化，能大致得出自己聲音的頻率范圍，也是挺有意思的。在做課程設(shè)計之前覺得內(nèi)容挺難的，但經(jīng)過查閱圖書館的資料和同學(xué)們的努力與幫助，最后還是以比較短的時間完成了這次課程設(shè)計。以前學(xué)matlab的時候，最后的大作業(yè)也是用gui設(shè)計了一個可視化界面，所以在本次設(shè)計中可視化界面的設(shè)計也沒有覺得很難。但是看到其他同學(xué)有用到edit text控件來作濾波器參數(shù)的輸入，感覺到自己

21、的能力還是很有限，所以還需要加強(qiáng)學(xué)習(xí)。但最重要的還是感覺到通過課程設(shè)計能夠?qū)W以致用，并且運用以前學(xué)過的工具來更好的理解所學(xué)的內(nèi)容，收獲還是挺大的。五、參考文獻(xiàn)程佩青 數(shù)字信號處理教程（第三版） 清華大學(xué)出版社羅軍輝、羅勇江、白義臣等 matlab7.0在數(shù)字信號處理中的應(yīng)用 機(jī)械工業(yè)出版社劉波、文忠、曾涯等 matlab信號處理 電子工業(yè)出版社六、謝辭在本次設(shè)計中，借閱了圖書館的一些書籍，比自己的幫助比較大，同學(xué)間的相互討論與幫助也起到了很重要的作用。此外還要特別感謝指導(dǎo)老師耐心的輔導(dǎo)，并幫助我糾正錯誤，授予以魚，亦之以漁，使我不僅能夠按時完成課程設(shè)計，也從中對本課程有了更深的認(rèn)識與理解，同時

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29、arest cab.for more information about making a claim to an employment tribunal, seeemployment tribunals.the (lack of) air up there watch mcayman islands-based webb, the head of fifas anti-racism taskforce, is in london for the football associations 150th anniversary celebrations and will attend citys

30、 premier league match at chelsea on sunday.i am going to be at the match tomorrow and i have asked to meet yaya toure, he told bbc sport.for me its about how he felt and i would like to speak to him first to find out what his experience was.uefa hasopened disciplinary proceedings against cskafor the

31、 racist behaviour of their fans duringcitys 2-1 win.michel platini, president of european footballs governing body, has also ordered an immediate investigation into the referees actions.cska said they were surprised and disappointed by toures complaint. in a statement the russian side added: we foun

32、d no racist insults from fans of cska.age has reached the end of the beginning of a word. may be guilty in his seems to passing a lot of different life became the appearance of the same day; may be back in the past, to oneself the paranoid weird belief disillusionment, these days, my mind has been v

33、ery messy, in my mind constantly. always feel oneself should go to do something, or write something. twenty years of life trajectory deeply shallow, suddenly feel something, do it.一字開頭的年齡已經(jīng)到了尾聲?；蛟S是愧疚于自己似乎把轉(zhuǎn)瞬即逝的很多個不同的日子過成了同一天的樣子；或許是追溯過去，對自己那些近乎偏執(zhí)的怪異信念的醒悟，這些天以來，思緒一直很凌亂，在腦海中不斷糾纏?？傆X得自己自己似乎應(yīng)該去做點什么，或者寫點什么

34、。二十年的人生軌跡深深淺淺，突然就感覺到有些事情，非做不可了。the end of our life, and can meet many things really do?而窮盡我們的一生，又能遇到多少事情是真正地非做不可？during my childhood, think lucky money and new clothes are necessary for new year, but as the advance of the age, will be more and more found that those things are optional; junior high s

35、chool, thought to have a crush on just means that the real growth, but over the past three years later, his writing of alumni in peace, suddenly found that isnt really grow up, it seems is not so important; then in high school, think dont want to give vent to out your inner voice can be in the high

36、school children of the feelings in a period, but was eventually infarction when graduation party in the throat, later again stood on the pitch he has sweat profusely, looked at his thrown a basketball hoops, suddenly found himself has already cant remember his appearance.童年時，覺得壓歲錢和新衣服是過年必備，但是隨著年齡的推進(jìn)

37、，會越來越發(fā)現(xiàn)，那些東西根本就可有可無；初中時，以為要有一場暗戀才意味著真正的成長，但三年過去后，自己心平氣和的寫同學(xué)錄的時候，突然就發(fā)現(xiàn)是不是真正的成長了，好像并沒有那么重要了；然后到了高中，覺得非要吐露出自己的心聲才能為高中生涯里的懵懂情愫劃上一個句點，但畢業(yè)晚會的時候最終還是被梗塞在了咽喉，后來再次站在他曾經(jīng)揮汗如雨的球場，看著他投過籃球的球框時，突然間發(fā)現(xiàn)自己已經(jīng)想不起他的容顏。originally, this world, can produce a chemical reaction to an event, in addition to resolutely, have to d

38、o, and time.原來，這個世界上，對某個事件能產(chǎn)生化學(xué)反應(yīng)的，除了非做不可的堅決，還有，時間。a persons time, your ideas are always special to clear. want, want, line is clear, as if nothing could shake his. also once seemed to be determined to do something, but more often is he backed out at last. dislike his cowardice, finally found that t

39、here are a lot of love, there are a lot of miss, like shadow really have been doomed. those who do, just green years oneself give oneself an arm injection, or is a self-righteous spiritual.一個人的時候，自己的想法總是特別地清晰。想要的，不想要的，界限明確，好像沒有什么可以撼動自己。也曾經(jīng)好像已經(jīng)下定了決心去做某件事，但更多的時候是最后又打起了退堂鼓。嫌惡過自己的怯懦，最終卻發(fā)現(xiàn)有很多緣分，有很多錯過，好像冥

40、冥之中真的已經(jīng)注定。那些曾經(jīng)所謂的非做不可，只是青蔥年華里自己給自己注射的一支強(qiáng)心劑，或者說，是自以為是的精神寄托罷了。at the moment, the sky is dark, the air is fresh factor after just rained. suddenly thought of blue plaid shirt; those were broken into various shapes of stationery; from the corner at the beginning of deep friendship; have declared the end

41、 of the encounter that havent start planning. those years, those days of do, finally, like youth, will end in our life.此刻，天空是陰暗的，空氣里有著剛下過雨之后的清新因子。突然想到那件藍(lán)格子襯衫；那些被折成各種各樣形狀的信紙；那段從街角深巷伊始的友誼；還有那場還沒有開始就宣告了終結(jié)的邂逅計劃那些年那些天的非做不可，終于和青春一樣，都將在我們的人生中謝幕。baumgartner the disappointing news: mission aborted. r plays a

42、n important role in this mission. starting at the ground, conditions have to be very calm - winds less than 2 mph, with no precipitation or humidity and limited cloud cover. the balloon, with capsule attached, will move through the lower level of the atmosphere (the troposphere) where our day-to-day

43、 weather lives. it will climb higher than the tip of mount everest (5.5 miles/8.85 kilometers), drifting even higher than the cruising altitude of commercial airliners (5.6 miles/9.17 kilometers) and into the stratosphere. as he crosses the boundary layer (called the tropopause),e can expect a lot of turbulence.the supersonic descent could happen as early as s