EVENT_SOUND is a Game Event.
This event is triggered upon playback of any sound, and allows hard coded sounds to be altered in a context-aware fashion. The RETURN variable is set to the sound effect number of the sound that is being played. Set RETURN to the sound you want to be played instead, or set it to -1 to cancel playback. THISACTOR is set to the id of the actor playing the sound ('globalsound' and 'screensound' sounds will default to the player)