What's that noise?

Do you ever hear things during the night and can't figure out what it is? Yesterday I woke up very early in the morning because I kept hearing this strange whistling noise. It almost sounded like a baby wheezing. I could for the life of me figure out what it was. It was bugging the crap out of me so I had to get up and figure it out.

Tanner had fallen asleep with his recorder in his mouth and when he exhaled it would whistle. I had to wake him up to take it away and he kept insisting he was awake the whole time. He had planned on waiting for me to go to sleep so that he could get up and practice during the night. He is trying to get better than Sarah but he never has time to practice. I guess he couldn't outlast me and he finally crashed with it still in his mouth.