Section: Input/Ouput Functions
portaudio library was available
when FreeMat was built.  The syntax for the command is one of:
wavplay(y) wavplay(y,sampling_rate) wavplay(...,mode)
where y is a matrix of audio samples.  If y has two columns, then
the audio playback is in stereo.  The y input can be of types 
float, double, int32, int16, int8, uint8.  For float and 
double types, the sample values in y must be between -1 and
1.  The sampling_rate specifies the rate at which the data is 
recorded.  If not specified, the sampling_rate defaults to 11025Hz.
Finally, you can specify a playback mode of 'sync' which is synchronous
playback or a playback mode of 'async' which is asynchronous playback.
For 'sync' playback, the wavplay function returns when the playback is
complete.  For 'async' playback, the function returns immediately (unless
a former playback is still issuing).