Our Sweet Slumber Sound Machine stopped working properly a couple of months after we bought it. The "nightlight" turns on randomly and when that happens you can't turn the machine off unless you unplug it completely. We brought it with us when we went camping and it worked fine with batteries the first time, but never again. We can't use it unless we plug it in, which means it's useless for camping. The machine does not play loudly enough, either.
I would not buy this again. I think the HoMedics SS-2000 is a better purchase, although it can sound a bit "tinny".