The sound of people eating.
I usually need to eat alone if I can. Hearing other people eat drives me insane. And my husband has an effed up schedule so he gets up and eats his dinner at 4am while I'm trying to sleep. He watches tv with his headphones in therefore he can't hear himself chewing and slurping. Normally he eats like a human being but not at 4am. I've talked to him about it but it hasn't made a difference. I just lay there in bed thinking the worst. Lately I just get up and try to work on my computer with the sound up loud but I really just want to sleep. I also hate the sound of liquid pouring like late at night when it's quiet - I feel like my head's going to explode.