Not quite "white" noise
My wife wanted a white noise generator to drown out the early-rising birds outside our bedroom window.  So I bought a SleepMate 580A about a month ago.  It does cover-up the bird sounds.  But as other reviewers have noted, it's quite loud - if I don't use earplugs, I wake in the morning with ringing in my ears.  But my real dissatisfaction is that within the nice whooshing white noise, you can distinctly hear the hum of the fan motor (60-cycle hum).  Maybe my unit is defective, or maybe I'm more sensitive to motor hum than most people.  I'm going to try the Marsona 1288A.
Rating: 3 stars