The sounds of the race track (cars starting, tires being taken off and put on, how they sound when they rush by you-gives me chills just thinking of it!)
Sounds like thishttp://www.youtube.com/watch?v=If-uoCcpNsAYeah, I know I'm a weirdo!

My fan when I'm in bed at night.

Oddly enough just having the tv on is calming to me.