I have a lot of little noise issues. If there is an alarm clock anywhere in a house, I can't sleep. Actually, any repetitive noise with pauses completely keeps me from sleeping. Fans or other white noise is totally fine. Radios, television, alarms, telephones, loud talking, snoring, people playing Scrabble... if it's not a continuous noise, it wakes me up, and then it makes me mean. I just lie in bed focusing on the noise, hating whoever is making the noise until it's all I can do not to go on a rampage with a baseball bat.
Chalkboards. Just chalkboards. The sound of chalk on them, the smell, seeing fingers touching chalkboards... scratching makes me scream in pain. I have no idea why I'm so sensitive to them, but I am. It's not good that my college is almost exclusively equipped with chalkboards.