Works well.
Purchased for ADD son who needs something to block out distractions when trying to go to sleep. Was pleased to find this as I had one of the original units like this that I inherited from my great-grandfather (I used it because I could never get used to sleeping without a window unit air conditioner in the fall and winter months). The older unit was actually a little louder than this new one but it seems to work fairly well. It helps my son fall to sleep most nights but doesn't necessarily KEEP him asleep...but then that's not what it's supposed to do.<br /><br />All in all a great device.
Rating: 4 stars