Pandoras Box > Devices and Layer Parameters > Audio Tracks

The Playback Transport channel allows setting the play mode of the audio file to Play Once, Stop, Pause and Play Loop.

External Control via DMX, Widget Designer, etc.

You can control all playback parameters externally. For DMX control, the chapter DMX Tables lists all parameter information, for other external control e.g. via the Widget Designer the Parameter List is of interest.