If life-threateningly, call an ambulance.
If loud, loud music or earplugs or those headphones that also cover your ear and blot out extraneous noise.
If persistently annoying, close and lock door to your room (depending on whether roommate refers to sharing an actual room, or sharing an apartment, which varies).
Otherwise, I can't help you; later tomorrow, you may want to discuss this with your roommate and explain why it bothers you and ask if they could either tone down the alcohol or else try to behave a bit better when drunk, but there's no doing that successfully until they're sobered up and past the hangover (if any).
EDIT: You... may want to call 911 about that if your roommate gets any worse or shows any signs of having passed out. Otherwise, in between vomiting, try to get them to drink water and/or gatorade-type stuff, but don't force him to, especially if he complains about an upset stomach. If it's going to come up anyway, there's no point, and the goal here is to avoid dehydration. Make sure your roommate does not drown in vomit or the toilet. Under no circumstances give your roommate acetaminophen (tylenol, I believe); ibuprofen (advil) is fine.
ADDITIONAL EDIT: When I say pass out, I mean more of a blackout type of thing. If they just fall asleep, they are probably fine-ish; it can be hard to tell the difference, I guess, I don't have much practical experience. Check to ensure a steady pulse and breathing, is what I'd do but honestly this isn't a situation I've been in myself.
FINAL EDIT: The acetaminophen thing isn't going to have immediate consequences, it's just that the combination of that particular drug and alcohol can best be described as a Liver Disaster. One instance probably won't have a noticeable effect, but it could, and that shit does some really nasty stuff to your liver. They synergize really badly.