Play a wav audio file and duplicate speed for part of it and keep the rest running with the orginal speed in MATLAB

I want to play a part of WAV audio file with different speeds for example double speed and keep the rest of the file working normally with the original speed.

% snd is a wav file last 20 seconds.
  specPart = snd((2:7) * 2)  % I took a part of it and doubled its speed
  sound(specPart , FS) % this will be played in  double speed

Now I want to play all snd files including the specPart inside of it.

Answer 1

[Geoff Hayes]

Hussein - I'm guessing that your (2:7) is just an example and that you really want to speed up more than just the 6 samples of data. You could try the following, using a MATLAB sample sound file

 load handel.mat

which gives us a sampling frequency, Fs, of 8192, and an array of 73K samples, y (so nearly nine second of data). Suppose that we want to speed up the fourth and fifth seconds. We can do

 fourthSecondSample = 8192*3 + 1;
 sixthSecondSample  = 8192*5 + 1;

 % get every second sample for the fourth and fifth seconds
 sampledData = y(fourthSecondSample:2:sixthSecondSample-1);

 % create the new sound array with the sampled sound data
 yp = [y(1: fourthSecondSample-1); sampledData; y(sixthSecondSample:end)];

 % play the sound with the sampled data
 sound(yp,Fs);

Answer 2

[Walter Roberson]

Extract the data you want and sound() it with Fs*2 as the rate.