A lot of people mention the eating/slurping/chomping thing but I can take that a step further, because one of my all time pet peeves that makes me disgusted and frustrated beyond words is when I am trying to transcribe a report where the doctor who is dictating is eating or chewing gum while dictating. I wear a headset and they are talking into a mouthpiece, so it is virtually someone smacking and slurping right in my ear and it's enough to make me want to rip my headset off and throw it after awhile when they keep doing it. I am one of the least violent people I know, but if the person doing that were to walk into the room after having to listen to that for awhile, I'd truly want to smack them!

I don't like the chalkboard either, and I can't stand it when people by me are popping their knuckles or bones. My mom has a real problem with the sound of styrofoam. I also get annoyed if someone in a movie theater sitting near me keeps rattling a wrapper or bag on something they are eating.