Could Listening to Colored Noise Help You Get More Sleep?

White, pink, brown or green? Discover the benefits of each sleep sound for insomnia, anxiety and more

Alexa Pellegrini,

AARP

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Published October 03, 2024

Paul Spella

You’ve probably heard about white noise, a static-like sound that some people swear by for catching more z’s, but today there is a rainbow of colored noises growing in popularity. Unpleasant sounds in our environment, from barking dogs to disruptive neighbors to the constant hum of traffic, can leave us exhausted. But what if the right color of noise could turn your bedroom into a restful retreat?

Older Americans are increasingly searching for ways to get better shut-eye. One AARP survey found that nearly half (48 percent) of older adults struggle to get enough sleep.

And in a survey conducted by the Sleep Doctor about which sleep sounds Americans prefer, 40.1 percent of respondents said they prefer green noise, 38.1 percent said white noise, 14.7 percent said pink noise and 13.8 percent said brown noise.

“Soothing sounds help the brain and nervous system by reducing stress and promoting relaxation through the activation of the parasympathetic nervous system,” says Dan Berlau, a professor of pharmaceutical sciences at the Regis University School of Pharmacy in Denver. Additionally, he said, colored noise can mask disruptive environmental sounds and help lift mood and reduce anxiety.

Mathias Basner, M.D., a professor in the department of psychiatry at the University of Pennsylvania School of Medicine in Philadelphia, says that the benefits of sleep noise aren’t just in the relaxing sound that some of us find so calming. He says there may be more to it than that. “It’s a stimulus control in the sense that before you go to bed, you switch the white noise machine on and it’s a sign for your body to rest,” Basner says. “So putting white noise on becomes a ritual that may help you fall asleep.”

True colored noise has no variations; rather it’s a steady tone played at a certain frequency. There are sounds all around us, such as floor fans and ocean waves, that mirror the frequency patterns of each color. So if the idea of listening to colored noise to sleep seems odd, consider that you’ve already listened to approximations of these sounds — and chances are, they’ve helped you relax, even just a little. Here’s a rundown of how different types of colored noise differ and the health benefits they might have to offer, plus what science says about the possible side effects.

White noise

White noise combines all the frequencies of sound we can hear at the same volume, which makes it a great tool for masking intrusive sounds in our environment. Think of it like white light, where all the wavelengths of the color spectrum combine at an equal intensity.

What does white noise sound like?

Television static
A whirring fan
A vacuum cleaner

What are the benefits of white noise?

White noise remains one of the most popular sleep aids. In a survey conducted by the American Academy of Sleep Medicine, 47 percent of U.S. adults said they sleep with a fan on. Research backs this habit. One study published in Frontiers in Neurology found that white noise helped people fall asleep 38 percent faster compared to silence. In an AARP survey of nearly 2,500 Americans age 40-plus, 45 percent of respondents said they believed that a white noise machine could be very or somewhat effective, and 9 percent said they used one. And if you’re trying to put your fussy grandchild to bed, science shows white noise might ease colic.

Research is finding that the benefits of listening to white noise extend beyond sleep — it could help children with attention-deficit/hyperactivity disorder (ADHD) too. This might be explained by stochastic resonance (SR), a phenomenon in which random external noise helps neurotransmitters communicate and, in turn, enhances brain function. For instance, a study published in the Journal of Child Psychology and Psychiatry found that as a result of SR, when children with ADHD listened to continuous white noise, they showed enhanced memory and overall stronger cognitive performance.

Dopamine levels decline with age, so older adults with ADHD may also benefit by pressing play. (For more, see “ADHD in Older Adults: Diagnosis and Treatment.”)

Pink noise

Pink noise combines all the frequencies of sound we can hear with the highest frequencies played at a slightly lower volume than white noise. In other words, it’s slightly deeper than white noise, which some find more relaxing.

What does pink noise sound like?

Ocean waves
Light, steady rainfall
The distant roar of traffic

What are the benefits of pink noise?

Pink noise doesn’t just sound pleasant — it could even enhance slow waves in the brain, says Caroline Lustenberger, a group leader and lecturer at Eidgenössische Technische Hochschule Zürich (ETH Zürich), a public research university in Switzerland. These brain waves occur during deep sleep, and they’re key to memory consolidation and “trimming weak neural connections to make room for new ones,” she explains. In other words, they might help remove waste products and toxic proteins that accumulate during the day and may contribute to Alzheimer’s disease.

In one study, Lustenberger’s team found that pink noise both increases slow waves and improves post-sleep heart function in healthy, middle-aged men. However, Lustenberger also notes that in a separate long-term study, listening to pink noise had no significant effect on older adults’ slow waves.

Researchers at the University of Texas at San Antonio also found that listening to pink noise helped adults achieve deeper sleep. But compared to non-pink noise users, they showed impaired creativity and cognitive insight (experiencing fewer “a-ha!” moments) when they were given a number-reduction task immediately after sleeping for eight hours.

“Not everyone experiences a beneficial effect of slow waves,” Lustenberger says. “We have noted a reduction in mood and some changes in REM sleep, but we are uncertain whether these are negative side effects that could have undesirable long-term implications. More research is needed.”

What about the other noise colors?

You can also listen to grey noise, blue noise, violet noise and black noise. Know the differences between each tone, since not all of them are ideal for helping you sleep.

Grey: This smoother and more balanced spin on white noise blends all frequencies of sound at equal intensity. It offers a more balanced version of classic white noise sounds, such as television static.
Blue: More energy in the higher frequencies of sound creates a lively, stimulating noise ideal for focusing and busting fatigue. It sounds like steam escaping from a pipe.
Violet: A more intensified version of blue noise, violet noise further amps up the energy in the higher frequencies of sound. It sounds like a high-pitched whine, like a dentist’s drill. [/End sidebar]

Brown noise

Brown noise (also called red noise) combines all the frequencies of sound we can hear with the higher frequencies played at a very low volume. It has the most extreme adjustments and it’s deeper in tone than pink noise. Many find brown noise the most relaxing, since humans prefer lower-frequency sounds, Berlau says.

What does brown noise sound like?

Rumbling thunder
A waterfall
A shower with intense pressure

What are the benefits of brown noise?

Brown noise could not only help you sleep better, but it may also alleviate ADHD symptoms. For years, it’s made waves across TikTok for helping people of all ages rest and relax. The how and why are inconclusive, but experts suspect that, like white noise, brown noise could help stimulate the auditory system and, in turn, decrease distractions. A small study of 22 college students suggested it could even help boost working memory, which tends to decline in older adults.

Brown noise is also a popular pick for masking tinnitus. This condition, which is more common with age, causes you to hear sounds that other people can’t, such as ringing, buzzing or hissing, making it difficult to fall asleep. In one study on tinnitus retraining therapy with colored noise, tinnitus sufferers chose brown noise second only to white noise for relief.

However, the research on whether colored noise helps tinnitus is mixed. A review published in JAMA Otolaryngology — Head & Neck Surgery found that regularly masking tinnitus with colored noise could age the auditory system.

“Hearing is an active process,” Basner explains. “Basically, the inner ear translates fluctuations in air pressure into a meaningful signal and sends that to the brain for interpretation, and metabolic by-products are being generated. At some point, the auditory system needs to recuperate.”

Green noise

Unlike the other colored noise, green noise isn’t as strongly defined. As the name implies, it represents natural sounds in the mid-range frequencies with minimal variations in volume.

What does green noise sound like?

Birdsong
A breeze blowing through the trees
A babbling brook

What are the benefits of green noise?

If birds chirping puts you in a better mood, it’s not your imagination: Recent research in Proceedings of the National Academy of Sciences found that hearing birdsong decreased annoyance and stress. Listening to water was also linked with better health outcomes.

What’s more, a meta-analysis of 15 studies about listening to nature sounds showed that green noise may lower resting heart rate, blood pressure and respiratory rate (how many breaths you take per minute), along with promoting better mental health.

What color noise is best for sleep?

There is no gold standard for colored noise. “To date, no systematic studies have compared the effectiveness of different noise types, such as white or pink noise in comparable settings, in improving sleep,” Lustenberger says.

So, experiment with sleep sounds using the safety tips below until you find one that works best for you.

What are the best sleep sound apps?

These free and paid apps have excellent reviews.

White Noise Lite (free to download and use)
myNoise (free to download and use on a desktop; more sounds unlocked via donation)
Slumber (free to download; $39.99 per year for premium access)
BetterSleep (free to download; $59.99 per year for premium access)
Calm (free to download; $69.99 per year for premium access)

How to safely listen to colored sleep sounds

We still don’t know if listening to colored noises for sleep has long-term consequences for our health. But missing important noises around you is a risk. “Think about your toddler or grandchild crying in the next room, or think about a smoke alarm,” Basner says. “Colored sounds also mask those noises.”

It’s also important to check how many decibels your color noise machine emits, Basner says. These devices are powerful and can pose a danger to older adults with preexisting hearing loss who crank up the volume. Several machines Basner and his colleague bought from Amazon for testing emitted up to 75 decibels — 5 decibels higher than the safe upper limit. Some machines emit as many as 85 decibels, according to the Occupational Safety and Health Administration.

Make sure to put colored sleep noise machines and apps on a timer, since most people use these devices to fall asleep, not stay asleep. It’s a simple way to give your ears and brain a break, Basner recommends.

And if you’re still struggling to get quality rest, don’t suffer through counting sheep — talk to your doctor about it. “Maintaining a balanced and high-quality sleep, including … minimizing sleep fragmentation and frequent awakenings, is crucial for healthy aging,” Lustenberger says. Prolonged insomnia is linked to diabetes, obesity and many other health conditions that impact older adults, and taking sleeping medication isn’t the only way to get relief.

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