Problems using the function audiowrite

Hello, I'm working with Matlab R2014b and trying to create a wav file. I tried two posibilities:

 - wavwrite(int32(signal),Fs,24,['test2.wav'])  
 - audiowrite(['test.wav'],int32(signal),Fs,'BitsPerSample',24)

But when I try to heard both files, I can only heard the first one created with the old function wavwrite.

In both case is the same signal.

any help?

Answer 1

[Nick Haddad]

There is one subtle difference between writing 24-bit audio with audiowrite vs. wavwrite.

When writing int32 as 24-bit audio in wavwrite, the data range in y is interpreted as:

     –2^23 ≤ y ≤ 2^23–1

When writing an int32 as 24-bit audio in audiowrite, the data range in y is interpreted as:

     -2^32 ≤ y ≤ 2^32–1

So your data is still being written but slightly quieter. If your 'signal' variable is in the 24-bit range you will need to rescale it to the 32-bit range to get the same results as using wavwrite. If 'signal' is just a normalized double (-1 ≤ y ≤ 1), the you can simply supply the double value and audiowrite will scale it for you properly:

     audiowrite(['test.wav'],signal,Fs,'BitsPerSample',24)

[ignacio]

Thanks Nick, the code works perfectly ;)