Thread Subject: How to decrease sampling rate of voice signal??

Hi guys!!

I want to decrease sampling rate of voice signal.
(8khz,8bits,7sec to 4khz,8bit,7sec)


I need 4khz, 8bits, 7.0sec signal.

here is my source

[xx, fs, bits] = wavread('OriginVoice');

yy = decimate(xx,2);

t1 = (1:length(xx))*1/fs;
t2 = (1:length(yy))*1/(fs/2);

sound(yy);
wavwrite(yy, fs, 8, 'resample_4k');

plot(t1,xx,t2,yy), grid on;
legend('original','decimated');


please help me......


Using function of decimate, I got 4khz, 8bits signal.
However, running time of signal also was made half....
(4khz,8bits,3.5sec)

I don't understand why playing time of original signal
also was decreased by the function.

How can I get 4khz, 8bits signal with original running time
(7sec)?

try, if you shouod have acces to signalprocessing-toolbox

>> help downsample

http://www.mathworks.com/access/helpdesk/help/toolbox/signal/

Remember, you've decimated it, which is basically halving the sampling
frequency. If you play it at the original sampling frequency, it will
only run for half the time. You can either play it after interpolation
(which might make sense if you are doing all this for data storage
reduction) at the same 8kHz frequency, or when you play it (or save
it), make sure you change the sampling frequency specification (in
wavwrite change fs to fs/2).