Sleep is a vital—and complex—component of your overall wellbeing. As we learn more about what happens while we sleep, it’s become clear that the quality of your sleep is just as important as the quantity. A number of rigorous studies have identified a simple method that not only encourages deep, restful sleep, but also demonstrably improves your memory! It’s called pink noise, and we’ve gathered everything you need to know to get started.
How Acoustic Stimulation Improves Your Sleep—and Your Memory!
A recent study headed by Dr. Phyllis Zee, professor of neurology at the Feinberg School of Medicine at Northwestern, confirms the powerful impact of a specific type of acoustic stimulation and improved sleep quality. Zee and her collaborators found that a pattern of sound waves called “pink noise” enhanced a phase of the sleep cycle called slow wave sleep (SWS). This part of the sleep cycle, which we casually call deep sleep, is part of the no-rapid eye movement (NREM) cycle and is crucial for memory consolidation.
All the study participants spent two nights in a sleep lab. Each time they took a memory test at night, went to sleep wearing headphones and an electrode cap, and repeated the memory test in the morning. On one of the nights, however, a series of short bursts of pink noise were played through the headphones. “The noise is fairly pleasant,” says Zee. “It’s just noticeable enough that the brain realizes it’s there, but not enough to disturb sleep.”
Zee and her fellow researchers found that on the mornings after the pink noise sessions, participants’ memory test scores were, on average, three times better than the mornings after silent sessions. The improvement correlates to increased quality of deep, or SWS sleep. These findings, the researchers say, indicate that pink noise could be an effective way to enhance sleep quality and improve memory. “This is an innovative, simple, and safe non-medication approach that mat help improve brain health,” says Zee.
What Exactly Is Pink Noise?
Most of us are familiar with the term white noise, but what exactly is pink noise? Pink noise is a specific combination of high and low sound frequencies that sounds more balanced and natural than white noise. Pink noise sounds gentle and soothing, with each octave possessing equal energy. Zee compares the sound of pink noise to “a rush of water.”
For the study mentioned above, the pink noise was timed to match participants’ slow wave oscillations, which Zee and the researchers believe is part of why it was so effective. They hope to develop an affordable device that people can use at home to generate the same results. In the meantime, Zee says that simply playing pink noise is likely to improve the quality of your sleep, and consequently, your memory.
If you like to have a fan running while you sleep, you’re already enjoying the effects of pink noise! Some other ways to play pink noise at home would be streaming the sound of a steady rain fall of the wind from an app or website on your phone or computer. You can also purchase sound machines that emit pink noise. Why not give it a try and see if you notice a memory boost?