Q:

Is it safe to soundproof a bedroom that doesn't have an air vent?

I'm looking to soundproof my apartment bedroom. The bedroom itself has a single-pane window, relative thick carpet, and a cheap hollow core door. It has no air vents, only a hot water baseboard heater.
I'm primarily concerned about sounds coming from within the unit. It seems that they transfer in primarily through the door. Long term I do want to do something about external sounds as well but I think my only option there is acoustic curtains (or whatever they're called)
I understand that I should be adding a door sweep, and acoustic tape to the door frame to form a seal. However, I'm wondering if there's any health risks associated with low oxygen because the only way for air to get in is around the door.
Are there risks? Should I form a close but not tight seal? Any other ideas?
I'm also considering add a hallway runner to the hallway, and some art there to break up the noise before it gets to my door. 

A:

How big (in m3 not m2) is your bedroom? What I mean how much air is in there? I’m not sure that there is a danger that you will run out of air? Although it is a good thing to have source of fresh air.

