MATLAB的語(yǔ)音信號(hào)頻譜分析報(bào)告.doc

實(shí)驗(yàn)一y,fs,bit=wavread(I do)%讀取音樂(lè)片段，fs是采樣率size(y)%求矩陣的行數(shù)和列數(shù)y1=y(:,1);%對(duì)信號(hào)進(jìn)行分列處理n1=length(y1);%取y的長(zhǎng)度t1=(0:n1-1)/fs;%設(shè)置波形圖橫坐標(biāo)figuresubplot(2,1,1);plot(t1,y1); %畫出時(shí)域波形圖ylabel(幅值);xlabel(時(shí)間（s）);title(信號(hào)波形);subplot(2,1,2);Y1=fft(y1);w1=2/n1*(0:n1-1);%設(shè)置角頻率plot(w1,abs(Y1);%畫頻譜圖title(信號(hào)頻譜);xlabel(數(shù)字角頻率);ylabel(幅度);grid on;sound(y,fs); 實(shí)驗(yàn)二y,fs,bit=wavread(I do)y1=y(:,1);n1=length(y1);D=2;%設(shè)置抽樣間隔 y2=y1(1:D:n1);%減抽樣n2=length(y2);%減抽樣后信號(hào)長(zhǎng)度t2=(0:n2-1)/fs;%設(shè)置橫坐標(biāo)figure subplot(2,2,1);plot(t2,y2); %繪制減抽樣信號(hào)波形圖ylabel(幅度);xlabel(時(shí)間（s）);title(2:1減抽樣信號(hào)波形);Y2=fft(y2); %對(duì)y2進(jìn)行n2點(diǎn)fft譜分析w2=2/n2*0:n2-1;subplot(2,2,3);plot(w2,abs(Y2);%繪制減抽樣信號(hào)頻譜圖title(2:1減抽樣信號(hào)頻譜);xlabel(數(shù)字角頻率w);ylabel(幅度);grid on;sound(y2,fs/D);D=5;%設(shè)置抽樣間隔 y3=y1(1:D:n1);%減抽樣n3=length(y3);%減抽樣后信號(hào)長(zhǎng)度t3=(0:n3-1)/fs;%設(shè)置橫坐標(biāo)subplot(2,2,2);plot(t3,y3); %繪制減抽樣信號(hào)波形圖ylabel(幅度);xlabel(時(shí)間（s）);title(5:1減抽樣信號(hào)波形);Y3=fft(y3); %對(duì)y2進(jìn)行n2點(diǎn)fft譜分析w3=2/n3*0:n3-1;subplot(2,2,4);plot(w3,abs(Y3);%繪制減抽樣信號(hào)頻譜圖title(5:1減抽樣信號(hào)頻譜);xlabel(數(shù)字角頻率w);ylabel(幅度);grid on;sound(y3,fs/D)實(shí)驗(yàn)三y,fs,bit=wavread(I do)y1=y(:,1);n1=length(y1);n3=0:n1-1;b1=cos(0.75*pi*n3);%設(shè)置調(diào)制信號(hào)b2=cos(0.5*pi*n3);c1=b1.*y1;%對(duì)原信號(hào)進(jìn)行調(diào)制c2=b2.*y1;lc1=length(c1);t=(0:lc1-1)/fs;figure %用載波對(duì)信號(hào)進(jìn)行調(diào)制，并對(duì)其做fft變換subplot(2,2,1) %獲取頻譜，從圖中可以觀察到，調(diào)制后的plot(t,c1); %信號(hào)頻譜發(fā)生搬移xlabel(時(shí)間(s);ylabel(幅度);title(調(diào)制后信號(hào));subplot(2,2,2) %獲取頻譜，從圖中可以觀察到，調(diào)制后的plot(t,c2); %信號(hào)頻譜發(fā)生搬移xlabel(時(shí)間(s);ylabel(幅度);title(調(diào)制后信號(hào));w1=2/lc1*0:lc1-1;%設(shè)置角頻率WC1=fft(c1);C2=fft(c2);subplot(2,2,3)plot(w1,abs(C1);xlabel(數(shù)字角頻率w);ylabel(幅度);title(調(diào)制后信號(hào)的頻譜(高頻率調(diào)制);grid on;subplot(2,2,4)plot(w1,abs(C2);xlabel(數(shù)字角頻率w);ylabel(幅度);title(調(diào)制后信號(hào)的頻譜(低頻率調(diào)制);grid on;sound(c1,fs); 實(shí)驗(yàn)四clear all;cla;close alla,fs,bit=wavread(I do);y1=a(:,1);%去單列數(shù)據(jù)進(jìn)行分析f1=fft(y1);n=length(f1);tn=(0:n-1)/fs;w=2/n*0:n-1;%sound(y1,fs);figure(1)subplot(2,3,1);plot(tn,y1);grid on;title(音頻);xlabel(時(shí)間);ylabel(幅度);subplot(2,3,4);plot(w,abs(f1);grid on;title(頻譜);xlabel(頻率/pi);ylabel(幅度);t=0:n-1;y2=cos(pi*1/2*t);%載波函數(shù)y3=y1.*y2;%信號(hào)調(diào)制ty3=(0:length(y3)-1)/fs;subplot(2,3,2);plot(ty3,y3);%繪制調(diào)制后信號(hào)波形圖grid on;title(AM調(diào)制音頻信號(hào));xlabel(時(shí)間);ylabel(幅度);f3=fft(y3);n2=length(f3);w2=2/n2*0:n2-1;subplot(2,3,5);plot(w2,abs(f3);%繪制調(diào)制后信號(hào)頻譜圖grid on;title(AM調(diào)制頻譜);xlabel(頻率/pi);ylabel(幅度); %解調(diào)后信號(hào)n3=length(y3)t2=0:n3-1;y4=cos(pi*1/2*t2)y5=y3.*y4;%解調(diào)后的信號(hào)函數(shù)subplot(2,3,3);plot(t2,y5);grid on;xlabel(時(shí)間);ylabel(幅度);title(AM解調(diào)音頻信號(hào));f5=fft(y5);w3=2/n3*0:n3-1;subplot(2,3,6);plot(w3,abs(f5);%繪制解調(diào)后信號(hào)頻譜圖grid on;title(AM解調(diào)頻譜);xlabel(頻率/pi);ylabel(幅度); %設(shè)計(jì)巴特沃斯濾波器進(jìn)行濾波去噪N1,wc1=buttord(0.05,0.17,1,15);%確定低通濾波器的階數(shù)和截止頻率；b,a=butter(N1,wc1);%確定低通濾波器分子分母系數(shù)H,W=freqz(b,a);figure(2)plot(W,abs(H);%低通濾波器波形xlabel(w);ylabel(H);title(低通濾波器波形);m=filter(b,a,y5);wavplay(m,fs);lm=length(m);%濾波后信號(hào)長(zhǎng)度tm=(0:lm-1)/fs;%設(shè)置橫坐標(biāo)wm=2/lm*0:lm-1;M=fft(m);figure(3)subplot(2,1,1);plot(tm,m);grid on;title(濾波后波形);xlabel(t);ylabel(幅度);subplot(2,1,2);plot(wm,abs(M);title(濾波后波形頻譜圖);xlabel(w/pi);ylabel(幅度);%矩形窗和布萊克曼窗N=33;wc=0.3*pi;%基于經(jīng)驗(yàn)的指標(biāo)，其中N為理想低通濾波器階數(shù)，wc為截止頻率hd=ideal(N,wc);%調(diào)用理想低通濾波器函數(shù)w1=boxcar(N);%產(chǎn)生各種窗函數(shù)w2=blackman(N);h1=hd.*w1;%加窗設(shè)計(jì)各種FIR濾波器h2=hd.*w2;th1=(0:32)/fs;th2=(0:32)/fs;M=21184;fh1=fft(h1,M);%矩形窗頻譜函數(shù)w=2/M*0:M-1;fh2=fft(h2,M);%布萊克曼窗頻譜函數(shù)figure(4)subplot(2,2,1);plot(th1,h1)title(矩形窗時(shí)域);subplot(2,2,2);plot(w,abs(fh1);title(矩形窗頻域);subplot(2,2,3);plot(th2,h2);title(布萊克曼窗時(shí)域);subplot(2,2,4);plot(w,abs(fh2);title(布萊克曼窗頻域)%解調(diào)后信號(hào)n3=length(y3)t2=0:n3-1;y4=cos(pi*1/2*t2)y5=y3.*y4;%調(diào)制后的信號(hào)函數(shù)figure %濾波處理y6=conv(h1,y5);%用矩形窗對(duì)調(diào)制后信號(hào)進(jìn)行濾波f6=fft(y6);n4=length(f6);ty6=(0:n4-1)/fs;w3=2/n4*0:n4-1;%sound(y6,fs);figure(5)subplot(2,2,1);plot(ty6,y6);title(矩形窗濾波后音頻)subplot(2,2,2);plot(w3,abs(f6);title(矩形窗濾波后頻譜)y7=conv(h2,y5);%用布萊克曼窗進(jìn)行濾波f7=fft(y7);n5=length(f7);ty7=(0:n5-1)/fs;w4=2/n5*0:n5-1;%sound(y7,fs);subplot(2,2,3);plot(ty7,y7);title(布萊克曼窗濾波后音頻)subplot(2,2,4);plot(w4,abs(f7);title(布萊克曼窗濾波后頻譜)實(shí)驗(yàn)五clc;clear;close;y,fs,bit=wavread(I do);y0=y(:,1);l=length(y0);%加三余弦混合噪聲t0=(0:l-1)/fs;d0=0.05*cos(2*pi*3000*t0);t1=(0:l-1)/fs;d1=0.05*cos(2*pi*5000*t1);t2=(0:l-1)/fs;d2=0.05*cos(2*pi*8000*t2);noise=d2+d1+d0;y1=y0+noise;%sound(y1,fs);a=length(noise);%繪制三余弦噪聲音頻圖wa=2/a*0:a-1;Noise=fft(noise);figure(1)subplot(2,3,4);plot(noise(1:150); xlabel(時(shí)間（s）)ylabel(幅值)title(三余弦信號(hào)音譜) subplot(2,3,1);%繪制三余弦噪聲頻譜圖plot(wa,abs(Noise);grid on; xlabel(W)title(噪聲頻譜)w0=2/l*0:l-1;%繪制加噪信號(hào)音頻Y1=fft(y1);subplot(2,3,5)plot(w0,abs(Y1);grid on; xlabel(W)title(加噪信號(hào)頻譜)ly1=length(y1);ty1=(0:ly1-1)/fs;subplot(2,3,2);plot(ty1,y1);xlabel(時(shí)間（s）)ylabel(幅值)title(加噪信號(hào)音譜) m=rand(l,1)-0.5; %產(chǎn)生幅度為0.5的隨機(jī)信號(hào)lm=length(m);y2=m+y0;%將噪聲信號(hào)與原聲音信號(hào)疊加wm=2/lm*0:lm-1;M=fft(m);figure(2)subplot(2,2,3);plot(m(1:150)xlabel(時(shí)間（s）)ylabel(幅值)title(白噪信號(hào)音譜)subplot(2,2,1);plot(wm,abs(M);grid on; xlabel(W)title(噪聲頻譜)l=length(y2);ty2=(0:l-1)/fs;w=2/l*0:l-1;Y2=fft(y2);subplot(2,2,4)plot(w,abs(Y2);grid on; xlabel(W)title(加噪信號(hào)頻譜)subplot(2,2,2);plot(ty2,y2);xlabel(時(shí)間（s）)ylabel(加噪信號(hào)幅值)title(加噪信號(hào)音譜); %設(shè)計(jì)濾波器進(jìn)行濾波去噪N1,wc1=buttord(0.04,0.17,1,30);%確定低通濾波器的階數(shù)和截止頻率；b,a=butter(N1,wc1); %確定低通濾波器分子分母系數(shù)m=filter(b,a,y1);%用濾波器濾除三余弦噪聲sound(m,fs);lm=length(m);%濾波后信號(hào)長(zhǎng)度tm=(0:lm-1)/fs;%設(shè)置橫坐標(biāo)figure(1);subplot(2,3,3);plot(tm,m);%繪制濾波后的波形xlabel(t(s)ylabel(信號(hào)幅值)title(去噪后信號(hào)波形); k=fft(m); %濾波后的波形做離散傅里葉變換w=2*0:length(k)-1/length(k);subplot(2,3,6)plot(w,abs(k);xlabel(w/pi)ylabel(幅度k)title(IIR濾波器濾波后信號(hào)頻譜);實(shí)驗(yàn)六.一clear all;clcy,fs,bit=wavread(I do);size(y)%查看讀取信號(hào)的聲道類型y1=y(: ,1);%對(duì)信號(hào)進(jìn)行分列處理n=length(y1);%求信號(hào)y1的的長(zhǎng)度t1=(0:n-1)/fs;f1=fft(y1);%對(duì)y1進(jìn)行fft譜分析w=2/n*0:n-1;%w為連續(xù)頻譜的數(shù)字角頻率橫坐標(biāo)%sound(y,fs);%播放音樂(lè)信號(hào)figure(1)subplot(2,1,1);plot(t1,y1);title(音樂(lè)信號(hào)的波形);xlabel(t);ylabel(y1);subplot(2,1,2);plot(w,abs(f1);title(音樂(lè)信號(hào)的頻譜);xlabel(w);ylabel(f1);%用IIR濾波器濾波（低）n2,wc2=buttord(0.15,0.20,1,15);%確定低通濾波器的階數(shù)和截止頻率；B2,A2=butter(n2,wc2); %確定低通濾波器分子分母系數(shù)H,W=freqz(B2,A2);figure(2)subplot(2,3,1);plot(W,abs(H);%低通濾波器波形xlabel(w)ylabel(H)title(低通濾波器波形); m2=filter(B2,A2,y1);%濾波lm2=length(m2);tm2=(0:lm2-1)/fs;subplot(2,3,2)plot(tm2,m2);xlabel(n)ylabel(信號(hào)幅值)title(低通濾波后波形); k2=fft(m2);%濾波后的波形做離散傅里葉變換l2=length(k2); w2=2*0:l2-1/l2;subplot(2,3,3);plot(w2,abs(k2);xlabel(數(shù)字角頻率w)ylabel(幅度)title(低通濾波后頻譜); %解調(diào)濾波后的頻譜%用IIR濾波器濾波（高）N,WC=buttord(0.15,0.20,1,15);%確定高通濾波器的階數(shù)和截止頻率；B,A=butter(N,WC,high); %確定高通濾波器分子分母系數(shù)H1,W1=freqz(B,A);subplot(2,3,4);plot(W1,abs(H1);%高通濾波器波形xlabel(w1)ylabel(H1)title(高通濾波器波形); m=filter(B,A,y1); %濾波lm=length(m);tm=(0:lm-1)/fs;subplot(2,3,5);plot(tm,m);xlabel(n)ylabel(信號(hào)幅值m)title(高通濾波后波形); k=fft(m);l2=length(k); w2=2*0:l2-1/l2;subplot(2,3,6);plot(w2,abs(k);xlabel(數(shù)字角頻率w)ylabel(幅度k)title(IIR高通濾波后頻譜);實(shí)驗(yàn)六.二clear all;clca,fs1,bit1=wavread(I do);b,fs2,bit2=wavread(風(fēng)聲);size(b)%查看讀取信號(hào)的聲道類型y2=b(:,1);%對(duì)信號(hào)進(jìn)行分列處理n2=length(y2);%求信號(hào)y2的的長(zhǎng)度t2=(0:n2-1)/fs2;f2=fft(y2);w2=2/n2*0:n2-1;%wavplay(y2,fs2);size(a)%查看讀取信號(hào)的聲道類型y1=a(: ,1);%對(duì)信號(hào)進(jìn)行分列處理n1=length(y1);t1=(0:n1-1)/fs1;f1=fft(y1);w1=2/n1*0:n1-1;%w為連續(xù)頻譜的數(shù)字角頻率橫坐標(biāo)%wavplay(y1,fs1);Fy1=abs(f1);%音樂(lè)1的幅度Ay1=angle(f1);%音樂(lè)1的相位Fy2=abs(f2);%音樂(lè)2的幅度Ay2=angle(f2);%音樂(lè)2相位F1=Fy1.*exp(j*Ay2);%音樂(lè)1的幅度與音樂(lè)2的相位交叉組合X1=ifft(F1);n3=length(X1);tx1=(0:(n3-1)/fs1;w3=2/n3*0:n3-1;%wavplay(real(X1),fs1);F2=Fy2.*exp(j*Ay1);%幅度相位交叉組合X2=ifft(F2);n4=length(X2);tx2=(0:(n4-1)/fs2;w4=2/n4*0:n4-1%wavplay(real(X2),fs2);figure(1)subplot(2,1,1);plot(t1,y1);%繪制信號(hào)1波形title(音樂(lè)信號(hào)1的波形);xlabel(t);ylabel(y1);subplot(2,1,2);plot(w1,abs(