You've heard before that white noise — aka constant, ambient sound — can help you fall asleep faster and snooze sounder. (Even the National Sleep Foundation recommends it for people who have trouble catching zzzs.) But there might be a more effective sleep soundtrack in town: pink noise.
As TIME defines it, pink noise is "a mix of high and low frequencies that sounds more balanced and natural" than the better-known white noise. And according to new research published in Frontiers in Human Neuroscience, pink noise just might be the secret to better sleep... and improved memory (bonus!).
In the small March 2017 study, Northwestern University researchers invited 13 adults age 60 or older to spend two nights in a sleep lab. Both nights, the participants took a memory test, went to bed wearing headphones and an electrode cap, and retook the memory test when they woke up.
One of the nights, no noise played through the participants' headphones. On the other night, however, pink noise was played in short bursts. These spurts were timed to match the slow, deep-sleep waves emitted by the participants' brains and detected by their electrode caps.
The results: When participants slept with pink noise playing, their slow-wave sleep oscillations increased, meaning they experienced more periods of deeper sleep. After a night with pink noise, participants also performed up to three times better on the morning-after memory test than they did after sleeping in silence.
These new findings back those from previous studies, which similarly found that pink noise increased slow-wave sleep oscillations and improved memory in young people.
But don't go deleting your white noise phone app quite yet. This new study was very small, and the researchers say we need more research on the long-term benefits to determine just how helpful pink noise is for sleep and memory.
Ultimately, the study authors hope to develop a user-friendly pink noise device that future study participants could use to test the long-term effects from the comfort of their own homes — and that all of us might be able to use in our own homes one day.
Until then, science is certain white noise can help you snooze more soundly, so if you struggle with catching quality zzzs, consider giving a white noise generator (or a fan, music, or nature sounds) a try.