White noise is a sound that is monotonous, with no sudden changes in volume or intensity, which imitates the sounds a baby hears during foetal life and is designed to have a calming and soothing effect, to help with sleep and even to help relieve pain and tension. Nowadays, many white noise devices and apps are available and, although practice confirms its effectiveness, experts still have doubts about the effects of white noise on hearing or mental development in the child.