I bought one and liked it--we used it mostly on the rain noise. But DD loves white noise, so once it went off, she would stir. I wish it would go longer than 40min. So then we bought her this sound machine and still use it to this day. Will probably get a 2nd one for this LO.
http://www.target.com/p/the-first-years-sounds-for-silence-nursery-sound-machine/-/A-12873665#prodSlot=medium_1_8&term=sound machine