If you just want "white noise" this is for you!
I love my Dohm Sound Conditioner!  I took it on a trip recently and it's great in hotel rooms that are too quiet.  It makes a sound similar to a fan blowing.  There is no rain sound that makes you want to run to the bathroom and no seagulls cawing over the sound of crashing waves, like you get with some other sound machines!  Just a steady woooshing sound that you can leave on all night.  It is also small enough that it is easily packed for travel.  Some of the reviews I read, said that it was too loud if it sits on the nightstand beside you.  I didn't find this true at all!  I thought, when it comes to blocking out distractions, the closer the better!
Rating: 5 stars