Plays the actor's ActiveSound, if one is defined. The sound is only played if the current tic is evenly divisible by eight. Contrary to what the name of this function implies, the sound is not looped. The only standard class that uses this function is WaterDropOnFloor, which uses it to make the sound slightly less repetitive.
For general sound playback, you probably want to use A_PlaySound instead.
This is from the WaterDropOnFloor actor that uses this sound.
Spawn: DRIP A 6 A_FLoopActiveSound DRIP BC 4 DRIP D 4 A_FLoopActiveSound DRIP EF 4 DRIP G 4 A_FLoopActiveSound DRIP H 4 Loop