@Don Juan Lol!

I've heard a door closing, a person inhaling sharply, and last night I heard someone talking - every time, I knew instantly that it was just hypnagogic hallucinations. Yes, those sounds can be INCREDIBLY real. That's how you know they're the HI or HA. I like LiveInTheDream's suggestion, there. Make it so that you can only hear or see hallucinations, if anything.