I don't typically this bug is a serious problem. This bug I've seen only with my Spiritualist, where when I use AOE skill. The sound of the attack (w/o bass or any boost) is playing repeatedly in the area, if you walk away it will start to become quiet, and if you move back into the area it'll start to play again. As far as I know it doesn't play when others around unless they were there when it was casted. It's not annoying to me, but I feel like I just should let you know. 
P.S : Relogging does fix it, traveling far distances, and loading ; teleporting.
Also if this bug has been reported already, just ignore or delete this thread. 
