2nd: Rhythmic Sound
3rd: Frequent Sound Using Water
These three videos all shared the similarity which is using frequent voice to calm those babies. It is believed that babies feeling insecure while they exposed to the outside world after being in womb for 9 months time.
While they staying in placenta, the flowing of amnion fluid sound makes the baby used to the environment they being in, which has been calm the babies. They feel secure while hearing back the similar frequency sound.
Lastly attached one more video to cheer you guys up :)
by Keah Mei Sian