★ What is Smart Baby Sleeper The SMART BABY SLEEPING microphone measures the sound level of the environment and automatically plays music, lullaby, etc. if your baby cries. If the one who starts to play does not cry or if the noise in the environment does not increase, it is a non-working baby sleep application.- Loud and effective (baby sleeper) sounds:- Effective melodies, lullabies, sounds colics.- works without the need for internet.- 21 different sound options.NOTE: The Smart Baby Sleeper application does not work in the background or when the phone is in sleep mode, so the smart working feature should not work on the front and your phone should not be in sleep mode.