MATLAB处理语音信号滤波程序.doc

MATLAB处理语音信号滤波程序

巴特沃思滤波器滤波
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%参数初始化%%%%%%%%%%%%%%%%
clearall;%关闭以往仿真的数据栈
A=5;%噪声的振幅
u1=0.01;%噪声振幅的衰减系数
u2=0.02;
u3=0.03;
f1=50;%多频噪声频率
f2=200;
f3=800;
[Y,fs,bits]=wavread('0601331007.wav')%读出信号1，采样率和采样位数
%sound(Y,fs);
%[X,Fs,bits]=wavread('0601331007.wav');%读出信号2，采样率和采样位数
n=length(Y);%求采样信号1的长度
%m=length(X);%求采样信号2的长度
t=0:1/fs:(n-1)/fs;%求采样信号1时域上的采样点数
%t1=0:1/Fs:(m-1)/fs;%求采样信号2时域上的采样点数
%%%%%%t=(0:n-1)/fs;
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%构造噪声%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
y1=u1*A*sin(2*pi*f1*t)+u1*A*sin(2*pi*f2*t)%两两噪声相加
y2=u1*A*sin(2*pi*f3*t)
y=y1+y2
%%%%%%Z1=u1*A*sin(2*pi*f1*t1)+u1*A*sin(2*pi*f2*t1)%两两噪声相加
%%%%%%Z2=u1*A*sin(2*pi*f3*t1)
%%%%%%Z=Z1+Z2
%figure(1)%画出噪声的时域图，取200个点
%%%%%%%%%%plot(t,y);gridon;
%plot(t(1:200),y(1:200));gridon;
%
%xlabel('时间(t)');
%ylabel('幅度（y)');
%title('噪声的时域图');
%
%Fy=fft(y,n);%对噪声进行傅立叶变换
%Fy1=abs(Fy);
%n1=floor(n/2);%对zhang求采样点数的一半
%n2=floor(m/2);%对zhanglow求采样点数的一半
%f=(0:n1)*fs/n;%时域上的采样点数
%f1=(0:n2)*Fs/m;%时域上的采样点数
%
%figure(2)%画出噪声的频谱图
%plot(f,Fy1(1:n1+1));gridon;
%xlabel('频率（f）');
%ylabel('幅度（Fy1）');
%title('噪声的频谱图');
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%加噪声前后的时域图比较%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
Y=Y(:,1);%此处假设声音是双声道的，只取单声道作分析
%X=X(:,1);%此处假设声音是双声道的，只取单声道作分析
Y1=y+Y';%对采样信号进行转置再加上噪声
%pause(10);%暂停10s
sound(Y1,fs);%读出加噪声后的采样信号
%figure(3)%画出加噪声前后的时域比较图
%subplot(2,1,1);plot(t,Y);gridon;
%plot(t(1:1000),Y(1:1000));gridon;
%xlabel('时间(t)');
%ylabel('幅度（Y)');
%title('加噪声前的时域图');
%
%subplot(2,1,2);plot(t,Y1);gridon;
%%%%%%%%%%plot(t(1:1000),Y1(1:1000));gridon;
%xlabel('时间(t)');
%ylabel('幅度（Y1)');
%title('加噪声后的时域图');
%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%加噪声前后的频域图比较%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%
%
%FY=fft(Y1,n);%对加噪声后的采样信号1进行傅立叶变换
%FY1=abs(FY);
%FY2=fft(Y,n);%对加噪声前的采样信号1进行傅立叶变换
%FY3=abs(FY2);
%FX=fft(X,m);%对加噪声前的采样信号2进行傅立叶变换
%FX4=abs(FX);
%
%figure(4)%画出加噪声前后的频域比较图
%subplot(2,1,1);
%plot