Is it legal or acceptable for apartment dwelling neighbors to play the stereo at deafening levels all day long?

This question is not about me. It’s about people I know, who don’t know I am asking and didn’t ask me to ask it, nor will they know I’m asking it (because then they could look at all my Fluther stuff and learn all about me!).

I’m just asking because reading their griping on FB makes me curious, so I figured I’d ask the collective.

These people live in a 3 family house. Apparently the walls are thin. Their neighbors play the stereo and deafening levels from 8 am to 10 pm. I know that after 10 or 11 pm, it’s supposed to be down or off, and that’s not their issue. Their issue is that the neighbor blasts it all day long.

Apparently the neighbors are not the most upstanding citizens, so it’s not likely that there will be any resolution. I am just wondering if this were to happen to any typical apartment dweller, what their recourse could be.

Is this legal or acceptable?