Additional Coverage:
- What the heck is pink noise? And why are scientists saying sleeping with it can harm your health? (the-independent.com)
Is Your Pink Noise Sleep Aid Doing More Harm Than Good? Researchers Say It Might Be Time to Rethink Your Bedtime Routine
For many, the gentle hum of pink noise has become a nightly ritual, promising a faster path to dreamland and a shield against disruptive sounds. Often likened to the soothing rhythm of heavy rainfall or ocean waves, pink noise – a lower-frequency cousin to white noise (think TV static) – is widely embraced, with machines offering both varieties. And for a while, the science seemed to back it up; a 2019 Northwestern study even suggested it could enhance deep sleep in those with mild cognitive impairment.
However, a new caution from researchers at Penn Medicine is turning this popular sleep solution on its head, suggesting pink noise might actually be detrimental to your sleep quality.
A recent Federal Aviation Administration-funded study, involving 25 healthy adults aged 21 to 41, found a concerning trend. Participants exposed to pink noise for a week experienced a nearly 19-minute decrease in REM sleep.
Why is this significant? REM (rapid eye movement) sleep is a critical component of overall brain health, playing a vital role in memory consolidation, emotional regulation, brain development, and even protecting against dementia, according to Harvard Health.
Dr. Mathias Basner, a professor of Sleep and Chronobiology in Psychiatry, emphasized the potential risks. “REM sleep is important for memory consolidation, emotional regulation and brain development, so our findings suggest that playing pink noise and other types of broadband noise during sleep could be harmful – especially for children whose brains are still developing and who spend much more time in REM sleep than adults,” Basner stated.
The study participants, who had no prior experience with sleep noise aids, slept for eight hours under various conditions, including exposure to aircraft noise, pink noise, and a combination of both, with and without earplugs.
The results were eye-opening. Earplugs proved significantly more effective at blocking out traffic noise.
Furthermore, the combination of pink and aircraft noise led to shorter deep and REM sleep periods compared to noise-free nights. Participants also reported waking up more frequently when exposed to aircraft or pink noise, a disruption that was mitigated when they wore earplugs.
These findings prompt researchers to call for more thorough investigation into sleep aids that utilize broadband noise, especially given the hundreds of millions of views white noise videos garner on platforms like YouTube. The implications for young children, whose brains are rapidly developing and who spend a greater proportion of their sleep in REM, are particularly concerning. Many parents commonly use sound machines to help infants and toddlers fall asleep, with REM sleep making up a quarter of an infant’s sleep cycle.
“Overall, our results caution against the use of broadband noise, especially for newborns and toddlers, and indicate that we need more research in vulnerable populations, on long-term use, on the different colors of broadband noise and on safe broadband noise levels in relation to sleep,” Basner concluded.
It seems the quest for a good night’s sleep might require a closer look at the very tools we’ve come to rely on.