Getting a good night’s sleep is critical to maintaining good brain health and overall health. Losing sleep has been linked to increased levels of markers that are tied to neurodegeneration, such as in Alzheimer’s disease. For millions of people, having adequate “sleep hygiene” means a mix of getting their sleeping environment just right, including the use of soothing sounds from musical melodies to nature sounds or white noise makers. Research suggests that if you’re using white noise (like a fan or white noise maker) to help you sleep, switching to pink noise can help you sleep and improve your memory.
Pink noise is similar to white noise in that it is a similar background buzz. Pink and white are characterized by the frequency (speed) of their sounds. While white noise is the most commonly thought of remedy to help you sleep, pink is the type of background noise that is most common in nature. Pink noise is the type of sound frequency found in waterfalls, rain, heartbeats, wind, and even rustling leaves.
A study funded by the Alzheimer’s Association recently investigated how the brain waves of people with mild cognitive impairment is altered during sleep. In brains of people with mild cognitive impairment or with Alzheimer’s disease, the slow wave activity is diminished. Slow wave activity is critical for the consolidation of memories which takes place in the brain each night during sleep. Using previous research that showed memory enhancement was possible in both young and older adults through the method of stimulating slow waves through audio waves, researchers at Northwestern University decided to see if it would make a difference in the brains of people with cognitive impairments.
They recruited nine adults with mild cognitive impairment between the ages of 63-80 to take a memory recall test based on pairing words together before they went to sleep. While they slept, they listened to “pink noise” inside a pair of headband speakers. Once they woke up, they repeated the same test they had taken the night before.
The pink noise had stimulated an increase of slow wave activity in their brains by over 10%. In half of the patients, memory recall increased after only one night of acoustic stimulation. The study was small and indicated that longer trials should be conducted to hone-in to how much pink noise is needed for an improvement in the brains of people that have already begun declining. The previous research by Northwestern University has shown improvement in memory of healthy older adults through pink noise, making it an easy biohack to incorporate in your bedtime routine.
You can find pink noise makers, pink noise fans, and even sleep headphones that have pink noise settings built-in. If you’re using a sleep app with music or nature sounds, there’s likely a pink noise setting that you can apply too. These comfortable Bluetooth wireless sleep headphones are an important part of some of my family members’ sleep hygiene, and they can be used for exercise too.
Kids can benefit from listening to soothing sounds at bedtime too, and these kids sleep headphones were a great tool for us as well. You don’t have to worry about hearing damage to children’s ears as they sleep because they have a volume limitation built-in. Sleep well!
Papalambros, Nelly A., et al. “Acoustic Enhancement of Sleep Slow Oscillations in Mild Cognitive Impairment.” Annals of Clinical and Translational Neurology, vol. 6, no. 7, 2019, pp. 1191–1201., doi:10.1002/acn3.796.
Papalambros, Nelly A., et al. “Acoustic Enhancement of Sleep Slow Oscillations and Concomitant Memory Improvement in Older Adults.” Frontiers, Frontiers, 21 Feb. 2017, www.frontiersin.org/articles/10.3389/fnhum.2017.00109/full.