Since 1978, Back to Sleep bear has been helping millions of newborns sleep in maternity hospitals and homes worldwide! It is the ONLY audio pacifier with an actual recording made inside a mother¹s womb! Back to Sleep bear's authentic womb sounds are universally recognized by babies and effective in lulling them to sleep in minutes! Soundbox has a 5 minute auto-shutoff timer to save batteries, with sound and motion sensors that reactivate recording when Baby cries or the bear is moved. Back to Sleep bear also comes with Silkie®, the natural bonding aid that retains parents’ scent and reassures Baby of their presence. 3 AAA batteries needed and included.