Consider this before you crank pink noise at bedtime
Add Axios as your preferred source to
see more of our stories on Google.
Illustration: Megan Robinson/Axios
Pink noise — which is often used to mask environmental sound and induce sleep — might actually reduce REM sleep, a new study in the journal Sleep suggests.
Why it matters: Noise machines have become a go-to sleep aid, particularly for babies, but they might interrupt crucial processes for brain health and happiness.
What they did: Researchers from the University of Pennsylvania Perelman School of Medicine had 25 healthy adults sleep in a lab, along with different combinations of aircraft noise, pink noise and earplugs.
- Between the lines: They chose pink noise over white noise, because a recent review suggested it might be better at promoting sleep.
What they found: Using pink noise increased light sleep and reduced REM sleep — which is connected with brain development, memory formation and emotional regulation.
Researchers urged caution about the widespread use of continuous sound to sleep.
- Caveat: The study was small, short-term and included environmental and pink sounds at a level higher than many people might hear them.
"I refuse to use the noise machine [for my 6-month-old]," says Kevin Woods, an auditory neuroscientist and director of science at music app Brain.fm, who wasn't involved with the study but says it affirmed his thinking about broadband noise.
- "You wouldn't sit your kid in front of a staticky TV screen for several hours a day," because that's not offering a visual that's helpful for the baby's development, Woods tells Axios. "I don't want to do that to the ears any more than to the eyes."
Instead of playing broadband noise, he recommends blackout curtains (which also block out sound) and other sound insulation to help with sleep, especially for babies.
The intrigue: Earplugs, according to the study, "emerged as clearly superior" at protecting sleep when there's environmental noise.
The bottom line: When it comes to deep sleep, quiet — not steady sound — is the dream.
