Recording of a mother's heartbeat or "womb whooshing" can provide instant relief by recreating the safe atmosphere of the womb.

Soft music or humming can reduce crying intensity and increase the duration of calmness. Colic Relief Tips for Parents - HealthyChildren.org

These sounds mask household noises and provide a consistent, soothing background that babies find familiar.

To quickly soothe a colicky baby, research suggests using low, rhythmic sounds that mimic the environment of the womb. These "white noise" sounds can help trigger a baby's natural calming reflex, allowing them to fall asleep faster during intense crying bouts. Quick Calming Sounds for Colic