Sleep Machine or Snore Machine?

Yesterday I jumped onto the bed to nap with Bob and he had his C-PAP thingy on. Everything was fine until his mouth opened while he was sleeping. Then all of a sudden he started making a continuous snore sound because the C-PAP blows air into his nose continuously and it was coming out of his mouth like his head was some kind of weird horn. It was so loud it woke him up and he closed his mouth to stop it. *laughs*