changing frequency of an existing audio

hi i have wrote a simple code as the following.

[y,fs] = audioread("Sound.wav");

sound(y,fs);

i know that i can change the sampling frequency of it by changing the "fs" value, my question is how can i change the frequency of the existing audio, i want it to play at 1000 hz for example.

Answer 1

[Mathieu NOE]

hello

the question is not 100 % clear to me

if you want to play the same signal to a different pitch , you can simply do

newfs = 1000;
sound(y,newfs);

but as the signal has not been resampled , the pitch will be different as if you had played it with the original sampling frequency fs

if you want to have the same pitch , you need also to resample / decimate the data

here is an example how to decimate the data (multi channel case here) , assuming the new sampling rate is a integer factor lower compared to the original sampling rate :

%% decimate (if needed)
% NB : decim = 1 will do nothing (output = input)
decim = 1;
if decim>1
    for ck = 1:channels
    newsignal(:,ck) = decimate(signal(:,ck),decim);
    newfs = fs/decim;
    end
end