Yes it is normal to hear the difference in noise when you breathe. Today's machines and masks are much quieter than they used to be. It does take a while to get used to it all, but it does happen. I find I can calm myself down by slowing my breathing which makes it quieter. You could always have your doctor adjust the ramp time down so you can get into a full sleep quicker. Many people start out using the machine for as long as they can tolerate and then increase the time used each night. I encourage you to keep on using the machine as untreated sleep apnea can cause very serious health problems. Come back for any more questions you may have.