Thread Subject: Problem with sound and soundsc on MATLAB 2009b, Mac (Snow Leopard)

Hi,

I'm having problems auditioning sound signals using the sound and soundsc functions in MATLAB 2009b on Mac Snow Leopard 10.6.1.

I can run the following code to generate a 1 second 440 Hz sine wave at 48 kHz, scaled by 0.5:

fs = 48000;
sig = 0.5*sin(2*pi*(0:(fs-1))*440/fs);

But when I run the code:

sound(sig,fs)

I hear the signal I expect along with some bad buzzing-type artefacts. If I write the signal to a wave file ( using wavwrite(sig,fs,'test.wav') ) and audition it using other audio software on the computer, it sounds perfect.

Has anyone any suggestions as to what might be going on?

Thanks,

Aengus.

Hi,

Some additional information. This appears to be a problem with Java audio on the Mac.

Some talk in these threads:

http://discussions.apple.com/thread.jspa?messageID=10397960&tstart=0
http://discussions.apple.com/thread.jspa?threadID=1250142&start=0&tstart=0
http://lists.apple.com/archives/java-dev/2009/Oct/msg00151.html .

At the suggestion of a poster in one of the threads, I got the buzzing to stop by running Applications/Utilities/Audio Midi Setup and setting the output audio sampling rate to 44100 Hz. This is only a temporary fix though, until another application changes the sample rate and things get messed up again.

Even with the temporary fix, I still hear a click a few hundred milliseconds into the sound playback, which is not present when using other non-Java applications.

I have seen mention of people going back to an earlier Java version. I don't know if this is a good idea or not... or how likely it is that there will be a proper fix soon.

Cheers,

Aengus.



"Aengus " <aengus@ee.usyd.edu.au> wrote in message <hc3ih8$f94$1@fred.mathworks.com>...
> Hi,
>
> I'm having problems auditioning sound signals using the sound and soundsc functions in MATLAB 2009b on Mac Snow Leopard 10.6.1.
>
> I can run the following code to generate a 1 second 440 Hz sine wave at 48 kHz, scaled by 0.5:
>
> fs = 48000;
> sig = 0.5*sin(2*pi*(0:(fs-1))*440/fs);
>
> But when I run the code:
>
> sound(sig,fs)
>
> I hear the signal I expect along with some bad buzzing-type artefacts. If I write the signal to a wave file ( using wavwrite(sig,fs,'test.wav') ) and audition it using other audio software on the computer, it sounds perfect.
>
> Has anyone any suggestions as to what might be going on?
>
> Thanks,
>
> Aengus.

For anyone else with this problem, a workaround that's not too bad is:

wavwrite(sig,fs,'temp.wav');
!afplay temp.wav

afplay is a command line soundfile player on OS X.

Cheers,

Aengus.


"Aengus " <aengus@ee.usyd.edu.au> wrote in message <hc3n1j$hkc$1@fred.mathworks.com>...
> Hi,
>
> Some additional information. This appears to be a problem with Java audio on the Mac.
>
> Some talk in these threads:
>
> http://discussions.apple.com/thread.jspa?messageID=10397960&tstart=0
> http://discussions.apple.com/thread.jspa?threadID=1250142&start=0&tstart=0
> http://lists.apple.com/archives/java-dev/2009/Oct/msg00151.html .
>
> At the suggestion of a poster in one of the threads, I got the buzzing to stop by running Applications/Utilities/Audio Midi Setup and setting the output audio sampling rate to 44100 Hz. This is only a temporary fix though, until another application changes the sample rate and things get messed up again.
>
> Even with the temporary fix, I still hear a click a few hundred milliseconds into the sound playback, which is not present when using other non-Java applications.
>
> I have seen mention of people going back to an earlier Java version. I don't know if this is a good idea or not... or how likely it is that there will be a proper fix soon.
>
> Cheers,
>
> Aengus.
>
>
>
> "Aengus " <aengus@ee.usyd.edu.au> wrote in message <hc3ih8$f94$1@fred.mathworks.com>...
> > Hi,
> >
> > I'm having problems auditioning sound signals using the sound and soundsc functions in MATLAB 2009b on Mac Snow Leopard 10.6.1.
> >
> > I can run the following code to generate a 1 second 440 Hz sine wave at 48 kHz, scaled by 0.5:
> >
> > fs = 48000;
> > sig = 0.5*sin(2*pi*(0:(fs-1))*440/fs);
> >
> > But when I run the code:
> >
> > sound(sig,fs)
> >
> > I hear the signal I expect along with some bad buzzing-type artefacts. If I write the signal to a wave file ( using wavwrite(sig,fs,'test.wav') ) and audition it using other audio software on the computer, it sounds perfect.
> >
> > Has anyone any suggestions as to what might be going on?
> >
> > Thanks,
> >
> > Aengus.