When your baby is crying and you don't know what to do, it can be quite stressful. The Sounds For Silence Nursery Sound Machine was co-developed with Dr. Harry Zehnwirth who has over 25 years of pediatric experience. Dr. Zehnwirth developed the unique sounds you will hear on your machine along with the Simple Secrets booklet. This program is an effective tool to help settle your baby quickly. Settled babies equal settled parents!