I also had some nights where my inhalations seemed noisier. Everything people have suggested could help. I lowered my machine so that it's below bed level, (but not low enough to collect dust bunnies), but I think the biggest help was changing the starting pressure at a higher number. Mine ramped from 4 - 12 in 20 minutes, and at 4 I was struggling to breathe! When I upped it to begin at 7, I felt better, and it wasn't so noisy. Perhaps this would help you... having said all that, a big factor in hearing something wrong, was that when the pollen count went up, my nasal passages got congested enough (and I'm not an allergic person) probably because I'm new to cpap and I'm feeling a tad ravaged by forced air traveling through my facial orifices, my mouth revolted and said "hell with the nose, breathe through me!!!" that caused all sorts of problems, including a loud sound which my husband also heard. Perhaps this is happening with you, too? My vote is it's either that the pressure is too low for you to start, and/or you're breathing through your mouth. I have your mask, too, and it doesn't seal as well as another (I'm trying a bunch out these first few months). I think we all fit best into different equipment given our facial structure. Thank god there's a bunch to choose from. I wish you speedy solutions!