You've probably heard of white noise machines, or maybe you've fallen asleep to the sound of a fan. But is white noise actually good for sleep? And what about pink noise, brown noise, and all the other colors? Here's what the science says.
White noise works by masking sudden changes in sound. Your brain is wired to respond to changes in your environment, even during sleep. A car horn or a door slamming triggers your brain's alert system. White noise creates a consistent sound blanket that covers up these sudden noises, allowing your brain to stay in deeper sleep stages.
Contains all frequencies at equal intensity. Sounds like TV static, a fan, or an air conditioner. It's the most commonly studied and effective at masking a wide range of environmental sounds.
Lower frequencies are louder, higher frequencies are softer. Sounds like steady rain, wind, or a heartbeat. A study in Frontiers in Human Neuroscience found that pink noise synchronized brain waves during deep sleep and improved memory consolidation.
Even more emphasis on low frequencies. Sounds like a deep rumble, ocean waves, or thunder. Many people find brown noise more pleasant and less harsh than white noise.
A 2021 meta-analysis in Sleep Medicine Reviews found that background noise improved sleep quality in noisy environments. A study in the Journal of Theoretical Biology found that continuous noise reduced time to fall asleep by 38% compared to silence.
Combine white noise with a consistent sleep schedule. Use our free Sleep Calculator to find your ideal bedtime.
At normal sleep volumes (under 50 dB), no. But some people crank machines up too loud, which can cause hearing damage over time, especially in children.
There's no evidence of harm from nightly use. If it helps you sleep, use it. It's similar to depending on a pillow or a dark room.
A fan produces a mix of white and pink noise. It works but the sound quality varies. A white noise machine produces consistent, adjustable sound without airflow.
White noise can help babies sleep (they're used to loud sounds from the womb). Keep the volume under 50 dB and place the machine at least 7 feet from the crib.