Playing sound files

Psiexp uses Unix commands afplay and sox to play sound files.

To play a file, use system() to execute an afplay or sox command.

Note

These commands can also be used in the macOS Terminal application. afplay is standard with macOS. sox is included with Psiexp. To make the sox command available in Terminal windows, add the following line to your .bash_profile

PATH=/Applications/Psiexp.app/Contents/Resources/libpsiexp/bin:$PATH

Using afplay

here are two ways to play soundFile.wav:

system("afplay soundFile.wav");
system(sprintf("afplay %s", "soundFile.wav"));

Using sox

With sox, you can modify how the sound is played:

system("sox soundFile.wav -d");  # play sound file
system("sox soundFile.wav -d pitch -100"); # lower pitch by 100 cents
system("sox soundFile.wav -d trim 0 1.5"); # only play first 1.5 seconds

Sox is very powerful and complicated. Documentation can be found here

Asynchronous use

The above commands wait until the sound file has finished playing before responding to any user interface events. To avoid this, use the readPipe() call:

player = readPipe(sprintf("sox -q \"%s\" -d", filename))

This returns immediately, and when this process is finished an event will be generated of type eof and source player