Sometimes it helps me to sleep if I put on some Enya or listen to some nature sounds (especially if I've watched a horror movie), but I don't require it. My brother, on the other hand, has to fall asleep watching South Park.
I have a box fan I put on all year regardless of cold/warmth. Due to rude neighbors with barking dogs and not wanting to commit homicide I put the fan on to drown out the noise and it works, along with a heavily insulated house.
(Which is why I have a CD player on a timer)
White noise