How do I find out if the person across the hall from me is a fellow ent?

I met my neighbour across the hall from me recently. I live in an apartment building full of mostly elderly individuals, so I don't see that many young people in the building. He is probably around late 20's early 30's. (I am 19) Whenever I go to do my laundry or take out my garbage it sounds like he's just chilling with friends or watching a movie. I just get this feeling from meeting him that he is a fellow ent and it would be nice to have a frient across the hall. What would be a good extremely subtle way to find out? I don't just want to be too obvious in case he isn't because I feel that would make things awkward.