This Type of Noise May Improve Sleep, Health and Memory

I know a few people who can’t fall asleep without the white noise of a fan in the room. The easiest way to define white noise is that it combines a large number of frequencies together into one sound.

And while that type of shushing noise may send some people into dreamland, researchers at Northwestern University have identified a sound that not only makes it easier to sleep, but also fights aging and improves your memory.

The sound they use is called “pink noise.” According to the researchers, pink noise is similar to the sound of a waterfall – it limits the higher sound frequencies that are found in white noise and boosts more of the lower frequencies. Here’s what it can do for you. . .

Improving Brain Waves

To get the best sleep effects of pink noise, say the Northwester scientists, its rise and fall should be synchronized to the rhythms of the slow brain waves that occur when you are dreaming during REM (rapid eye movement) sleep.

These slow brain waves incorporate oscillations that take place about once per second in contrast to the 10 oscillations a second that take place in the brain when you are awake.

In the Northwestern test of pink noise, the researchers tried out pink noise on 13 people who were over the age of 60. They found that the pink noise increased their periods of deep, refreshing slow-wave sleep and also improved their memories the next day (as evidenced by memory tests).1

“This is an innovative, simple and safe non-medication approach that may help improve brain health,” says researcher Phyllis Zee, who teaches neurology at the Northwestern University Feinberg School of Medicine. “This is a potential tool for enhancing memory in older populations and attenuating normal age-related memory decline.”

The Importance of Slow-Wave Sleep

While the researchers at Northwestern have focused on how pink noise can improve memory by strengthening the ability to get more slow-wave sleep, a review study at Berkeley indicates that improving this type of sleep may help you resist diabetes, stroke and heart disease as well as improve your efforts at keeping your weight down.2

“Nearly every disease killing us in later life has a causal link to lack of sleep,” says Berkeley researcher Matthew Walker. “We’ve done a good job of extending life span, but a poor job of extending our health span. We now see sleep, and improving sleep, as a new pathway for helping remedy that.”

The Berkeley scientists point out that the decrease in deep, satisfying, slow-wave sleep and an increase in restless, unrewarding sleep often starts when people are in their thirties. The researchers add that this alteration is accompanied by middle age memory complaints and physical maladies.

They are also at pains to point out that sleeping pills don’t help matters. Walker says that while pills can knock you out, they don’t help produce the natural sleep cycles that benefit the brain.

Getting Better Sleep

Along with playing pink noise when you go to bed, studies have shed light on other ways to improve your sleep.

A study at the Columbia University Medical Center in New York shows that you can increase your slow-wave sleep by eating more fruits and vegetables and cutting back on processed foods. In particular, the researchers found, eating foods high in sugar disturbs sleep and is likely to wake you up more at night.3

They also found that eating more protein can improve your chances of getting deeper, more rewarding sleep.

Another warning: You should avoid imbibing alcoholic beverages close to bedtime. A study in Australia demonstrates that bedtime drinking may help you fall asleep initially, but will disrupt your sleep later at night. The researchers found that alcohol disturbs your brain wave patterns so that your sleep is less restful.4

My advice – if you’re thirsty close to bedtime, drink water, but not too much if you want to avoid nighttime trips to the bathroom. Try out a sound machine that makes noises like rainfall or a waterfall to see if that helps you sleep. Plus, keep your bedroom dark and cool to aid your sleep.

And don’t forget to exercise during the day. Physical activity can help you sleep when you do some sort of activity every day. But it’s not an instant cure. If you haven’t been doing any exercise for a while, researchers generally say that one afternoon won’t do you much good. You have to be a consistent exerciser – at least take daily brisk walks – to reap its full sleep benefits.5


  1. https://www.ncbi.nlm.nih.gov/pubmed/28364428
  2. https://www.ncbi.nlm.nih.gov/pubmed/28384471
  3. https://www.ncbi.nlm.nih.gov/pubmed/26156950
  4. https://www.ncbi.nlm.nih.gov/pubmed/25597245
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3370319/