What Is Pink Noise and Can It Help Sleep and Memory?
There's a growing buzz around pink noise and brown noise and their possible effects on sleep, concentration and relaxation.
The science is new with only a few small studies behind it, but that hasn't stopped thousands of people from listening to hours of these noises on YouTube and on meditation apps.
To understand pink noise, start with white, the most familiar of the color noises.
White noise is similar to static on a radio or TV. It is defined as having equal volume across all the frequencies audible to the human ear.
The high frequencies of white noise can sound harsh. Pink noise turns down the volume on those higher frequencies, so it sounds lower in pitch and more like the natural sound of rain or the ocean.
Brown noise sounds even lower in pitch, creating a pleasing, calming sound.
What's the science behind color noises?
White noise and pink noise may provide small benefits for people with attention deficit hyperactivity disorder (ADHD), according to a recent review of limited ADHD studies. In theory, it wakes up the brain, said ADHD researcher and co-author Joel Nigg of Oregon Health & Science University in Portland.
"The noise provides stimulation to the brain without providing information, and so it doesn't distract," Nigg said.
White noise has also been used to treat tinnitus — a ringing sound in the ear.
Scientists at Northwestern University are studying how short pulses of pink noise can enhance the slow brain waves of deep sleep. In small studies, these pink-noise pulses have shown promise in improving memory and helping the body relax.
Northwestern's research could lead to a medical device to improve sleep or memory through personalized pulses of pink noise. But many scientific questions remain unanswered.
Is there any harm in trying color noises?
If color noises feel calming and help you drown out distractions, it makes sense to use them. Keep them at a quiet level, of course, to prevent hearing loss and take "plenty of breaks for the ears to rest," Nigg said.
