function [  ] = fftplot(hObject, eventdata, handles,h, x, Fs )

L = length(x);

NFFT = 2^nextpow2(L);               %確定FFT變換的長度

y = fft(x, NFFT)/L;

f = Fs/2*linspace(0,1,NFFT/2+1);    %頻率向量

axes(h);   %指定畫板

plot(f, 2*abs(y(1:NFFT/2+1)));      %繪制頻域圖像

grid on;

title(頻譜圖');

xlabel('Frequency (Hz)');

ylabel('|y(f)|');

由于這個是個人在GUI中使用的，因此有hObject, eventdata, handles這三個參數(shù)，具體GUI使用可以看附件

y    =  handles.y;

Fs   =  handles.Fs;

s = round(get(handles. slider17,'value')*length(y));

set(handles.text37,'string',num2str(s));

a= get(handles. slider18,'value');

Bz=[1,zeros(1,s),a];

Az=1;

y1=filter(Bz,Az,[y;zeros(length(y),1)]);

axes(handles.axes3);

plot(y1,'linewidth',2);

grid on;

h = handles.axes4;

fftplot( hObject, eventdata, handles,h,y1, Fs);

y是音頻數(shù)據(jù)，F(xiàn)s為采樣頻率，使用load 函數(shù)加載一個音頻即可得到

function pushbutton17_Callback(hObject, eventdata, handles)

% hObject    handle to pushbutton17 (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

fs   =  handles.Fs;  %多回聲

y    =  handles.y;

N =   handles.chong;

s = round(0.2*length(y));

a= 0.5;

Bz=[1,zeros(1,s)*N,a^N];

Az=[1,zeros(1,s),a];

y1=filter(Bz,Az,[y;zeros(2*length(y),1)]);

axes(handles.axes3);

plot(y1,'linewidth',2);

grid on;

sound(y1,fs);

guidata(hObject,handles);

N為多回聲的重數(shù)

最后面給出使用MATLAB錄音的一段GUI程序：

function pushbutton13_Callback(hObject, eventdata, handles)

% hObject    handle to pushbutton13 (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

num = [8000, 11025, 22050,44100];

value = get(handles.popupmenu3,'value');

Fs = num(value);

handles.rFs = Fs;

handles.R = audiorecorder(Fs,  handles.bits , handles.channel) ;

record(handles.R);

guidata(hObject,handles);

function pushbutton14_Callback(hObject, eventdata, handles)

% hObject    handle to pushbutton14 (see GCBO)

% eventdata  reserved - to be defined in a future version of MATLAB

% handles    structure with handles and user data (see GUIDATA)

stop(handles.R);

%play(handles.R);

%audiowrite('myaudio.wav');

guidata(hObject,handles);

      handles.y= getaudiodata(handles.R);

      handles.Fs =handles.rFs;

y    =  handles.y;

   Fs   =  handles.Fs;

     sound(a*y,v*Fs);