% m-file to take FFT of students' "open" and "give me'
% voce_fft.m
% 2/5/97, G. Dempsey
% Bradley University, Electrical & Computer Engineering

% get time domain info for 6 students

y1=wavread('h:\ee410\hw8\olee.wav');            % open for Lee
y2=wavread('h:\ee410\hw8\glee.wav');            % give me for Lee
y3=wavread('h:\ee410\hw8\ojoel.wav');
y4=wavread('h:\ee410\hw8\gjoel.wav');
y5=wavread('h:\ee410\hw8\ojeff.wav');
y6=wavread('h:\ee410\hw8\gjeff.wav');
y7=wavread('h:\ee410\hw8\ocurtis.wav');
y8=wavread('h:\ee410\hw8\gcurtis.wav');
y9=wavread('h:\ee410\hw8\okurt.wav');
y10=wavread('h:\ee410\hw8\gkurt.wav');
y11=wavread('h:\ee410\hw8\obecky.wav');
y12=wavread('h:\ee410\hw8\gbecky.wav');

% South-East U.S. Test Voices

y13=wavread('h:\ee410\hw8\ogary.wav');
y14=wavread('h:\ee410\hw8\ggary.wav');
y15=wavread('h:\ee410\hw8\odana.wav');
y16=wavread('h:\ee410\hw8\gdana.wav');


% eliminate DC content

m1=mean(y1);
m2=mean(y2);
m3=mean(y3);
m4=mean(y4);
m5=mean(y5);
m6=mean(y6);
m7=mean(y7);
m8=mean(y8);
m9=mean(y9);
m10=mean(y10);
m11=mean(y11);
m12=mean(y12);
m13=mean(y13);
m14=mean(y14);
m15=mean(y15);
m16=mean(y16);

y1=y1-m1;
y2=y2-m2;
y3=y3-m3;
y4=y4-m4;
y5=y5-m5;
y6=y6-m6;
y7=y7-m7;
y8=y8-m8;
y9=y9-m9;
y10=y10-m10;
y11=y11-m11;
y12=y12-m12;
y13=y13-m13;
y14=y14-m14;
y15=y15-m15;
y16=y16-m16;


% normalize data

y1=y1/max(abs(y1));
y2=y2/max(abs(y2));
y3=y3/max(abs(y3));
y4=y4/max(abs(y4));
y5=y5/max(abs(y5));
y6=y6/max(abs(y6));
y7=y7/max(abs(y7));
y8=y8/max(abs(y8));
y9=y9/max(abs(y9));
y10=y10/max(abs(y10));
y11=y11/max(abs(y11));
y12=y12/max(abs(y12));
y13=y13/max(abs(y13));
y14=y14/max(abs(y14));
y15=y15/max(abs(y15));
y16=y16/max(abs(y16));


disp('press key to continue- plot time domain')
pause

% plot voice in time domain for Lee and Becky

subplot(221),plot(y1)
ylabel('Amplitude')
title('Time Domain- "Open" from Lee')

subplot(222),plot(y2)
ylabel('Amplitude')
title('Time Domain- "Give Me from Lee"')

subplot(223),plot(y11)
ylabel('Amplitude')
xlabel('Data Length in bytes')
title('Time Domain- "Open" from Becky')

subplot(224),plot(y12)
xlabel('Data Length in bytes')
ylabel('Amplitude')
title('Time Domain- "Give Me" from Becky')

disp('Compute FFT')
pause


% setup code for frequency response of input signals (fft)

Npts=256;               % 256 pt FFT to distinquish freuencies
			% freq div= 8KHz/256= 31.25 Hz
x1=fft(y1,Npts);        % take FFT
x1=abs(x1);             % take absolute value
			% normalize data 
x1=x1/max(x1);

% do other voices

x2=fft(y2,Npts);
x2=abs(x2);
x2=x2/max(x2);

x3=fft(y3,Npts);
x3=abs(x3);
x3=x3/max(x3);

x4=fft(y4,Npts);
x4=abs(x4);
x4=x4/max(x4);

x5=fft(y5,Npts);
x5=abs(x5);
x5=x5/max(x5);

x6=fft(y6,Npts);
x6=abs(x6);
x6=x6/max(x6);

x7=fft(y7,Npts);
x7=abs(x7);
x7=x7/max(x7);

x8=fft(y8,Npts);
x8=abs(x8);
x8=x8/max(x8);

x9=fft(y9,Npts);
x9=abs(x9);
x9=x9/max(x9);

x10=fft(y10,Npts);
x10=abs(x10);
x10=x10/max(x10);

x11=fft(y11,Npts);
x11=abs(x11);
x11=x11/max(x11);

x12=fft(y12,Npts);
x12=abs(x12);
x12=x12/max(x12);

x13=fft(y13,Npts);
x13=abs(x13);
x13=x13/max(x13);

x14=fft(y14,Npts);
x14=abs(x14);
x14=x14/max(x14);

x15=fft(y15,Npts);
x15=abs(x15);
x15=x15/max(x15);

x16=fft(y16,Npts);
x16=abs(x16);
x16=x16/max(x16);

% plot Lee's and Becky's Voice in Freq Domain

% scale freq domain data back to analog freq
% only show 1st Npts/4 points (DC to 2000Hz)
% show above with x-axis in Hz

af_step=8000/Npts;
spersec=0:af_step:(1/Npts)*8000*((Npts/4)-1);

subplot(221),stem(spersec,x1(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Lee)')

subplot(222),stem(spersec,x2(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Lee)')

subplot(223),stem(spersec,x11(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Becky)')

subplot(224),stem(spersec,x12(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Becky)')

disp('Display next two students')
pause

subplot(221),stem(spersec,x3(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Joel)')

subplot(222),stem(spersec,x4(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Joel)')

subplot(223),stem(spersec,x5(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Jeff)')

subplot(224),stem(spersec,x6(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Jeff)')

disp('Display next two students')
pause

subplot(221),stem(spersec,x7(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Curtis)')

subplot(222),stem(spersec,x8(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Curtis)')

subplot(223),stem(spersec,x9(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Kurt)')

subplot(224),stem(spersec,x10(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Kurt)')

disp('Display next two students')
pause

subplot(221),stem(spersec,x13(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Gary)')

subplot(222),stem(spersec,x14(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Gary)')

subplot(223),stem(spersec,x15(1:Npts/4))
grid
title('"Open" Frequency Spectrum (Dana)')

subplot(224),stem(spersec,x16(1:Npts/4))
grid
title('"Give Me" Frequency Spectrum (Dana)')


% save data for ANN training

x1=x1(1:48);            % 0 to 1500 Hz only (48 inputs)
x2=x2(1:48);
x3=x3(1:48);
x4=x4(1:48);
x5=x5(1:48);
x6=x6(1:48);
x7=x7(1:48);
x8=x8(1:48);
x9=x9(1:48);
x10=x10(1:48);
x11=x11(1:48);
x12=x12(1:48);          % x13 thru x16 will be used for
x13=x13(1:48);          % test data
x14=x14(1:48);
x15=x15(1:48);
x16=x16(1:48);