I had a roommate at guitar camp one year who used a cPap. She wasn't in the room when I arrived, but I saw the machine, there, by the side of her bed, and thought - it's gonna be a llooong weekend. When I met her, she greeted me with a fresh packet of earplugs (oh, no!). When we retired for the night, she fixed her mask (she had the full mask) on her face, turned on the machine, and, I swear, it sounded like NORMAL BREATHING!