资源描述：
《语音信号采集与处理初步》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、语音信号采集与处理初步题目：1．语音信号的采集2．语音信号的频谱分析3．设计数字滤波器和画出频率响应4．用滤波器对信号进行滤波5．比较滤波前后语音信号的波形及频谱6．回放和存储语音信号一、语音信号的读入：[yfsnbit]=wavread('天后.wav');语音信号的播放：wavplay(y,fs);语音信号的存储：wavwrite(soutl,fs,'天后低通');二、滤波器的设计与分析：1.用fir1设计的低通滤波器代码如下：%设计FIR低通滤波器fp=1000HZ,fc1200HZ,Ap=1db,fs=2*fc-fp=1400HZ(阻带截频)，%wp=fp/Fs(抽样频率)=0.02
2、3*pi,ws=fs/Fs=0.032*pi,%由于As=100,这里选择Kaiser窗作为窗函数%计算可得A=-20lg(min{&p,&s})=100,由此可求阶数M,beta=0.1102(A-8.7)=10.06wp=0.023*pi;ws=0.032*pi;tr_width=ws-wpM=ceil((100-7.95)/tr_width/2.285)+1;beta=10.06;n=[0:1:M-1];wc=(ws+wp)/2;win=(kaiser(M,beta))';h=fir1((M-1),wc/pi,kaiser(M,beta));[H,w]=freqz(h,1);mag=a
3、bs(H);db=20*log10((mag+eps)/max(mag));subplot(3,1,1);stem(n,win);title('kaiserWindow')axis([0M-101.1]);xlabel('n');ylabel('w(n)')subplot(3,1,2);stem(n,h);title('ActualImpulseResponse')axis([0M-1-0.10.3]);xlabel('n');ylabel('h(n)')subplot(3,1,3);plot(w/pi,db);title('MagnitudeResponseindB');grid;axis
4、([01-15010]);xlabel('frequency(pi)');ylabel('Decibels')set(gca,'XTickMode','manual','XTick',[0,0.023,0.032,1])set(gca,'YTickMode','manual','YTick',[-100,0])低通滤波器的设计效果：2.高通滤波器的设计与选择：1）直接法设计的butterworth高通滤波器%设计IIR高通滤波器fp=5000HZ,fc=4800HZ;As=100db,Ap=1db%fs=2*fc-fp=4600HZ(阻带截频),wp=fp/Fs(抽样频率)=0.113*pi
5、,%ws=fs/Fs=0.104*piwp=0.113*pi;ws=0.104*pi;rp=1;rs=100;[N,Wn]=buttord(wp/pi,ws/pi,rp,rs);[b,a]=butter(N,Wn,'high');[h1,w]=freqz(b,a,256,2);plot(w,20*log10(abs(h1)));grid;title('High-passDF');2)双线性变换法设计的butterworth高通滤波器wp=0.113*pi;ws=0.104*pi;rp=1;rs=35;Fs=44100;wap=2*tan(wp/2);was=2*tan(ws/2);[n,wn
6、]=buttord(wap,was,rp,rs,'s');[z,p,k]=buttap(n);[b,a]=zp2tf(z,p,k);[bt,at]=lp2hp(b,a,wap););[bz,az]=bilinear(bt,at,Fs);[h,w]=freqz(bz,az,256,2);plot(w,20*log10(abs(h)));grid;title('High-passDF');3)用FIR1设计的高通滤波器：wp=0.113*pi;ws=0.104*pi;tr_width=wp-ws;M=ceil((100-7.95)/tr_width/2.285)+1;beta=10.06;n=[
7、0:1:M-1];wc=(ws+wp)/2;win=(kaiser(M,beta))';h=fir1((M-1),wc/pi,'high',kaiser(M,beta));[H,w]=freqz(h,1);mag=abs(H);db=20*log10((mag+eps)/max(mag));subplot(3,1,1);stem(n,win);title('kaiserWindow');axis([0M-10
