If silence is golden, then the Sound Oasis Sleep Sound Therapy System in blue is platinum. Numerous clinical studies have touted the benefits of white noise or continuous multi-frequency sounds that block out other noises and help you relax for helping your brain "downshift" from the active beta state to the relaxed "alpha" state, so that you can naturally fall asleep faster. A white noise machine can also help improve the quality of your sleep, helping you snooze more deeply and for a longer time. This sleep therapy sound machine has so many pleasant features and options, it"s like having a bit of spa luxury at your bedside. Choose from 6 soothing sounds: ocean surf, flowing stream, rain shower, white noise, summer night and gentle wind. Select the duration for automatic shut-off from 4 presets or let the machine lull you all night long. And talk about versatile! Use headphones or a speaker (sold separately) with the built-in jack and either plug the Sound Oasis machine in with the included AC adapter or drop in 4 AA batteries (sold separately) for more portable and cordless sleep therapy. This sound machine is equipped with exclusive sound card technology, so you can add more sounds to its repertoire with sound cards (sold separately). Use it as your everyday backlit alarm clock and wake up with a buzz or be gently roused by your favorite natural sound.