Just change the sound's description to one of the following.AudioDefaultLooping3DAudioCloseLooping3DAudioClosestLooping3DAudioLooping2DDon't think there's any more looping ones.
You won't be able to stop said sounds unless you use alxplay, which would only work on the host client, or if you played the sound on an object using playSound(slot,sound);
datablock AudioProfile(ambientSpace){ filename = "add-ons/filepath/ambientSpace.wav"; description = AudioLooping2D; preload = true;};function playRepeatingSound(%song){ for(%i=0; %i<clientGroup.getCount(); %i++) { %obj = clientGroup.getObject(%i); playSound(%obj, ambientSpace); }}