We have to sleep with whitenoise. We have a air cleaner that sounds like a loud fan. Twice we had to sleep without it. Once when the electrcity was out and once when our last one fried. Neither one of us slept those nights.
Here is an awesome website for whitenoise, etc. stuff. I plan on getting one of the fan cd's for hotel sleeping or whatever. They have something for everyone. They even have a vaccum cleaner one, my son would of loved that when he was a baby.
http://www.purewhitenoise.com/