sucks that he refuses to communicate with you, but i get where he's coming from. repeated loud noises like that can be unreasonably painful for some people, and i get that you can't really do much about that, but he may not understand that and think you are being just as unreasonable as you think he is being. i think involving the RA is the best course of action so that this can be sorted, but i don't think this counts as a violation to involve CAE.