A sleep sound machine is a device that produces a white noise to calm the listener, it's often used to

help lull newborns and kids to sleep, also have the same effect on adult.

A study by Webb et al. in 2015 found that premature babies exposed to their mother's heart rate

and voice recordings in the NICU had a significantly larger auditory cortex, the part of the brain

which is responsible for developing hearing and language skills.

Another study by Spencer et al.(1990), found that babies who listen to white noise fell asleep easier.

AEON's sleep sound machine with 20 different soothing sounds: heartbeat, natural sounds, lullabies,

white noise and etc. The sleep timer can choose 15, 30 or 60 minutes with the color indicator in

green, yellow and red. Besides, an optional professional sensor used to record and play mother's

real heart rate, this sensor probe got the patent in USA.