is white noise bad for older kids?

[indigosky]

Our 2 DDs (4 1/2 years, and 6 months) share a bedroom. As of recently, DD2 is doing well sleeping in her crib for the first part of the night (until now she's been in our bed 100% of the time), and that's working well for all of us. However, loud white noise seems to be part of the key for her.

Our question is, is it bad for our 4 1/2 year old to sleep a good part of her night with white noise blasting? Has there been any research on the effects of white noise on older children's brains, long-term effects on becoming a light vs. deep sleeper, etc?
Edited by indigosky - 6/20/12 at 7:52pm

[Bokonon]

I don't know about any studies, but my anecdotal experience is that my whole family sleeps with white noise machines and we can all fall asleep and stay that way without them.  We used to live on a busy street, and the white noise machines were necessary (my husband is a deep sleeper but I am not).  My kids can sleep with or without them, but it definitely helps drown out the little noises that might wake them up.