Photo credit: Pixabay
by Daniel Fink, MD, Chair, The Quiet Coalition
We can close our eyes and fall asleep on a sunny beach after lunch, but we cannot close our ears.
Hearing evolved eons ago to help animals either find food or avoid being eaten, and we can hear even when sleeping. Sensitive hearing when sleeping allowed animals, primates, hominids and modern humans to hear the crack of a twig from an approaching predator, the distant howl of a lion, a hungry newborn’s cry and these days, the horn-based alert of a neighbor’s car being locked remotely.
The Women’s World website has an article asking the question, “What is the best noise for sleep?” Most people are aware of white noise, but there are many different “colors” of noise. I was aware of pink noise, but the article lists brown, blue and violet, green and gray noises as well.
As the article notes, people can have trouble falling asleep or sleeping through the night. Having a neutral background noise can be soothing and mask sounds that might disrupt sleep. Reporter Isabelle Paquette admits that there’s little science behind which noise color might be best for sleep, but states that the best noise for sleep is the one that works for the person trying to sleep.
My answer? The best noise for sleep is quiet. This National Park Service noise map shows that without anthropogenic noise, nature is quiet. A study published in the Annals of Internal Medicine using simulated hospital noises showed that sounds as low as 35 A-weighted decibels (dBA)* can disrupt sleep. This study is behind the Annals’ paywall but can be found in a hospital or medical school library.
Natural quiet still exists in our noisy world. I have measured nighttime sounds at or even below 30 dBA at Lake Vyrny in Wales, the reservoir for Liverpool; in a remote village in the Alps, along le Tour de Mt. Blanc; and in Wupatki National Park in Sri Lanka. That type of natural quiet is the best noise for sleep.
*A-weighting adjusts unweighted sound measurements for the frequencies heard in human speech.
