This thread will probably be moved to the health and nutrition forum.
As the forum rules
"1. No online advice can replace direct veterinary intervention. If you suspect that your cat may be ill, please contact your vet immediately. You are welcome to look for advice in the health forum while waiting for that appointment, but never delay proper veterinary care waiting for Internet advice. Remember that cats, and especially kittens, are very adept in keeping pain to themselves and delaying treatment may cause irreversible damage.
The only people here are cat-lovers: there are no online veterinary consults of any kind here. And any vets who might post on this board do any treatment suggestions after seeing animals in person, at their place of employment, not online.
That said, I assume that loud noise damages cat ears just as it damages human ears. Only I don't know any cats who enjoy listening to loud noises, and therefore enjoy damaging their hearing (I know many humans who do). So, do your cats move away from the offending wall when your neighbor is playing music loudly? If not, the noise probably isn't bothering them, and they are probably fine.