obviously they see when the police arrive and turn it down. You should make a recording on your phone for the police with a shot of the time on the tv clock. Maybe play it over the phone for the dispatcher. Not sure what your town ordinances are for loud noise, but I'm sure there is a citation that has been issued. Make sure you tell the police when they arrive you would just like them to advise the neighbor to stop after certain hours. Or talk to the neighbor yourself. You could also write a nice letter and leave it for your neighbor explaining the hardship it causes you.
If you are a good tenant, your landlord won't want to lose you.