Up until I learned about LD's, i've always, always slept with the AC going just 5 feet away. It's not too loud, but just loud enough to maybe interrupt any conversations in that room.

I've heard that this kind of noise might mess up your dreams, since the mind wants to incorporate it into the dream somehow.
I've also heard that it will make you sleep lighter and may be beneficial for becoming lucid.

I have slept with that thing for about five years now, and it's difficult for me to fall asleep when it is off.
What i'm asking is, have any of you who are more experienced noticed problems when there's white noise going on in the background when you sleep?