Soothe and calm your baby with The First Years sounds for silence machine that plays 6 specially-developed white noises. It also plays 6 Mozart melodies that help your baby focus while you feed or massage. The sleep-timer function automatically turns off the baby sound machine after 60 minutes. This sound soother machine can be powered by electricity or batteries. The nursery sound machine was co-developed with experienced pediatrician Dr. Harry Zehnwirth. It comes with the "Simple Secrets for Settling Babies" booklet that has tips on settling crying babies.