6. Repetitive noises
Some people have a bad habit of making some kind of repetitive noise. For instance, you might tap your foot, flick your teeth, hit your pen against the side of the desk, sniff, or make a funny throat clearing sound.
If a person has to listen to another individual make the same noise again and again day after day, it can start to get on their nerves fairly quickly. The repetitive noise you like to make may comfort you on a subconscious level, but it is not soothing for anyone else.