语音信号处理与识别.docx

语音信号处理与识别

第一篇：语音信号处理与识别信号系统课程设计报告欧阳光亮2012029020025语音信号处理与识别目的：理解时域和频域尺度变换基本概念，掌握信号时频域分析方法，正确理解采样定理，准确理解滤波器的概念。内容：（1）使用Matlab中wavrecord命令录制一段3秒的语音信号，使用wavplay命令播放，录制命令和播放命令中的采样频率设置成相同和不同两种情况，对观察到的现象进行分析并结合课本中的知识对该现象进行解释；（2）使用不同的采样频率录制一段3秒的语音信号，画出信号的时域波形和频谱；找到语音信号的主要频谱成分所在的带宽；观察并分析不同采样频率对波形和频谱的影响；寻找声音信号不出现明显失真的最低采样频率；（3）录制一段男生的语音信号和一段女生的语音信号，对两段音频信号进行混合，设计滤波器将混合的语音信号分开成单独的男声和女声信号，如果分离效果不好，对原因进行解释。Matlab命令：wavrecord,wavplay,wavwrite,wavread,save,load,fft,fftshift,filter,plot,subplot,figure.过程:(1)相同：fs1=16000;%取样频率fs2=16000;%播放频率duration=5;%录音时间fprintf('Pressanykeytostart%gsecondsofrecording...n',duration);pause;fprintf('Recording...n');y=wavrecord(duration*fs1,fs1);%duration*fs是总的采样点数fprintf('Finishedrecording.n');fprintf('Pressanykeytoplaytherecording...n');pause;wavplay(y,fs2);wavwrite(y,fs1,'E:matlabrecord3.wav不同：fs1=16000;%取样频率fs2=8000;%播放频率duration=5;%录音时间fprintf('Pressanykeytostart%gsecondsofrecording...n',duration);pause;fprintf('Recording...n');y=wavrecord(duration*fs1,fs1);%duration*fs是总的采样点数fprintf('Finishedrecording.n');fprintf('Pressanykeytoplaytherecording...n');pause;wavplay(y,fs2);wavwrite(y,fs1,'E:matlabrecord3.wav');现象：第二次播放时，声音明显失真。理由：采样频率和播放频率不一样时声音信号会失真。（2）fs1=16000;%取样频率fs2=16000;%播放频率duration=5;%录音时间fprintf('Pressanykeytostart%gsecondsofrecording...n',duration);pause;fprintf('Recording...n');y=wavrecord(duration*fs1,fs1);%duration*fs是总的采样点数fprintf('Finishedrecording.n');fprintf('Pressanykeytoplaytherecording...n');pause;wavplay(y,fs2);wavwrite(y,fs1,'E:matlabrecord3.wav');wav=wavread('E:matlabrecord3.wav');Fs=16000;n=length(wav);f=(0:n-1)*16000/n;mag=abs(fft(wav));subplot(2,1,1);plot(wav);subplot(2,1,2);plot(f,mag)采样频率为1600010.5y/幅度0-0.5-101234x/t采样频率为16000567x1084600500400y/幅度***400060008000x/f***16000fs1=8000;%取样频率fs2=8000;%播放频率duration=5;%录音时间fprintf('Pressanykeytostart%gsecondsofrecording...n',duration);pause;fprintf('Recording...n');y=wavrecord(duration*fs1,fs1);%duration*fs是总的采样点数fprintf('Finishedrecording.n');fprintf('Pressanykeytoplayther