audiowrite audio file create

I should create an audio file with audiowrite, to save the same sound I can hear with sound function. How should I set function parameters?

    % code
load flux_adaptive_100
filename = 'flux_adaptive_100.wav';
audiowrite (filename,y,Fs);
clear y Fs
end

[Image Analyst]

What parameters? You already have y and Fs when you played the sound in the sound function, and you're specifying the filename, so what additional parameters do you think you need for audiowrite()?

[Marco Cornero]

sorry, i mean variables: in particular y and Fs. I tried to use the same Fs of sound function. My input matrix is 200000x1 double. I want to obtain a 2 seconds file. Thanks

[Geoff Hayes]

According to audiowrite, you are passing the correct parameters into the function call.

You mention a two second file...is that the first two seconds, or last two, or is your audio data just two seconds in length?

If you want the first two seconds, then you would do something like

 audiowrite (filename,y(1:2*Fs),Fs);

assuming Fs is the number of samples per second and 2*Fs is less than 200000.

[Marco Cornero]

I sampled a signal with a 1e-5 sample rate, which gave me the matrix I described before. If I choose Fs=100000 shouldn't be the file length = 2 seconds?

[Marco Cornero]

Using simple words: i want to save the sound i can hear using

sound(flux_adaptive_100,100000)

which is a 2 seconds length audio.

[Geoff Hayes]

If Fs is 100000 and your y is of length 200000, then it is two seconds in length. So

 audiowrite (filename,y,Fs);

is correct. Or are you saying that this doesn't work?

[Marco Cornero]

I'm saying that this doesn't work: now the length of the file is correct but there isn't any sound, while using

sound(flux_adaptive_100,100000)

the sound is hearable

[Geoff Hayes]

Okay. What are the units of y? You mention how y is an array of doubles, so what is the minimum and what is the maximum? What happens when you read the flux_adaptive_100.wav back into MATLAB? Can you hear any audio once you start playing it? If not, then check the samples and compare to those that you saved to file (what is the minimum and what is the maximum?).

[Marco Cornero]

if I open in matlab flux_adaptive_100.wav I obtain a column with constant value = 1

[Marco Cornero]

I found the solution!!! I had to write y=flux_adaptive_100(:,1)