Don't hesitate to confront them! That is your home, you pay the rent, and you have the right to be able to rest. If ya never confront them, they might not even know they're bothering anyone. Ya don't have to be a prick about it, just let them know that you need certain, reasonable hours of peace and quiet. Who knows, ya might even get an apology and some respect to boot. If they act like idiots about it, keep your cool and file complaints to the landlord (and let the landlord know that the police will be called if it keeps up).
I supervised an apartment complex for many years, you'd be surprised how many evictions I've seen due to uncooperative residents ignoring their landlords warnings about excessive noise. It's kind of stupid, but better them leaving than you!
Follow the proper channels, it's your home, you're untouchable, (especially if the police know whats going on).
Good Luck!