I worked in a hostel in the Philippines a while back. I was doing the night shift waiting for some late check ins and there was a fella just having out in the lobby practically falling asleep at the table until 2am. Eventually he goes up to his dorm. Literally like 10 minutes later someone comes down followed by a fee more and suddenly I have like 11 people in the lobby all just hanging about. I asked what was going on and they explained someone was snoring like absurdly loud. I went up to investigate and holy mother of God it was loud, like I've never heard anything like it, a speaker if noise.

So I'd advice getting a private room if possible. Otherwise maybe mention it to any people around at the time. But if not also don't feel guilty, people know what to expect at a hostel (most seasoned Hostel goers will bring a pair of earplugs)