What's that noise??

I slept next to my human last night, and was woken up by a really loud noise. It came from him.

I've heard this noise before, but it was so loud this time.

It was a kind of grunting, snorting noise, coming from his mouth.

I tried nose-nudging him.

I tried pawing him.

I tried staring at him.

He didn't wake up though.

Stupid human.