End point detection/Speech detection

hi i am doing project in matlab to find those points in a wav file (song) which are start and end points of vocals and the rest is considered noise and distcarted.. i have read book "Audio signal processing and recognition" by Roger Jang. this book has help to do EPD but it finds points of unvoiced sounds and i want code for EPD of voiced sounds.. i am pasting code of EPD from this book which find end points of unvoiced sounds.. please help me how can i modify it or write new code for EPD of voiced sounds.

waveFile='sunday.wav';
[wave, fs, nbits] = wavread(waveFile);
frameSize = 256;
overlap = 128;

wave=wave-mean(wave); % zero-mean substraction
frameMat=buffer2(wave, frameSize, overlap); % frame blocking
frameNum=size(frameMat, 2); % no. of frames
volume=frame2volume(frameMat); % volume
volumeTh1=max(volume)*0.1; % volume threshold 1
volumeTh2=median(volume)*0.1; % volume threshold 2
volumeTh3=min(volume)*10; % volume threshold 3
volumeTh4=volume(1)*5; % volume threshold 4
index1 = find(volume>volumeTh1);
index2 = find(volume>volumeTh2);
index3 = find(volume>volumeTh3);
index4 = find(volume>volumeTh4);
endPoint1=frame2sampleIndex([index1(1), index1(end)], frameSize, overlap);
endPoint2=frame2sampleIndex([index2(1), index2(end)], frameSize, overlap);
endPoint3=frame2sampleIndex([index3(1), index3(end)], frameSize, overlap);
endPoint4=frame2sampleIndex([index4(1), index4(end)], frameSize, overlap);

subplot(2,1,1);
time=(1:length(wave))/fs;
plot(time, wave);
ylabel('Amplitude'); title('Waveform');
axis([-inf inf -1 1]);
line(time(endPoint1( 1))*[1 1], [-1, 1], 'color', 'm');
line(time(endPoint2( 1))*[1 1], [-1, 1], 'color', 'g');
line(time(endPoint3( 1))*[1 1], [-1, 1], 'color', 'k');
line(time(endPoint4( 1))*[1 1], [-1, 1], 'color', 'r');
line(time(endPoint1(end))*[1 1], [-1, 1], 'color', 'm');
line(time(endPoint2(end))*[1 1], [-1, 1], 'color', 'g');
line(time(endPoint3(end))*[1 1], [-1, 1], 'color', 'k');
line(time(endPoint4(end))*[1 1], [-1, 1], 'color', 'r');
legend('Waveform', 'Boundaries by threshold 1', 'Boundaries by threshold 2', 'Boundaries by threshold 3', 'Boundaries by threshold 4');

subplot(2,1,2);
frameTime=frame2sampleIndex(1:frameNum, frameSize, overlap);
plot(frameTime, volume, '.-');

ylabel('Sum of Abs.'); title('Volume');
axis tight;
line([min(frameTime), max(frameTime)], volumeTh1*[1 1], 'color', 'm');
line([min(frameTime), max(frameTime)], volumeTh2*[1 1], 'color', 'g');
line([min(frameTime), max(frameTime)], volumeTh3*[1 1], 'color', 'k');
line([min(frameTime), max(frameTime)], volumeTh4*[1 1], 'color', 'r');
legend('Volume', 'Threshold 1', 'Threshold 2', 'Threshold 3', 'Threshold 4');