Babbling brooks, crashing ocean waves and falling rain—many people swear sounds like these help them fall asleep, but why?
Dr. Steven Bender, a clinical associate professor and director of the Center for Facial Pain and Sleep Medicine at the Texas A&M University College of Dentistry, said that white noise reduces the contrast between background sounds that you are familiar with, like the sound of your ceiling fan, with unfamiliar sounds, like a sudden car alarm.
“Your brain stays engaged with your environment even while you are sleeping, resulting in microarousals every 20 to 60 seconds,” Bender said. “At these points of arousal, the brain determines whether it is still safe to sleep.”
Thus, soothing sounds like rain falling or waves crashing on the beach can keep the brain feeling comfortable and at ease during sleep. However, there is no single sound that is comforting to everyone. “What you find calming depends on who you are and how you were brought up,” Bender said. “You have to try different things to determine what your brain likes during sleep.”