vacuum cleaners,heavy boots on a hard wood floor,car horns,the beeping sounds the cash registers used to make in Wal mart,any loud and sudden noise, mice running in the attic when I'm trying to sleep.This bothered me so bad I had fantasies of shooting thru the ceiling with a gun,And I HATE guns and I try to never harm a living being but those mice were really punching my buttons.Thankfully we found their place of entrance and blocked it.and a lot of the other stuff people mentioned.Thank goodness for the nice sounds like birdsong.