What Are Pink and Brown Noise and How Do They Affect Your Brain?

There's a reason white noise videos on YouTube rack up hundreds of millions of views: They help us to relax. Countless people rely on the soothing sound of a whirring fan or radio static to unwind, especially at bedtime. While white is likely the most commonly recognized "color" of noise, other shades can have an impact on the brain, as well.

The color of a noise is determined by its mix of frequencies. That steady hum of white noise is produced by equal distribution of energy across all audible frequencies. Pink noise boosts lower frequencies, and brown noise picks up the lowest frequencies, like the sound of thunder or a roaring waterfall.

Beyond their potential to induce relaxation and sleep, certain colors have shown potential benefits within neurodivergent circles and helped with focus. This is because certain hues of sound change the base "state" of the brain, says doctor of audiology Amy Sarow, AuD.

The Color of Sound

Brown noise triggers relaxation because of its similarities to the brain's resting state, Sarow says. The low frequencies of brown noise create a deeper sound that many people find soothing. There are even brown noise playlists curated with babies in mind because it's said to mimic the sound inside a mother's womb.

There's also potential beyond relaxation. Some small studies have shown that auditory noise can help to improve memory in children with ADHD. Andrew Kahn, PsyD, associate director of behavior change and expertise at Understood, points to the Moderate Brain Arousal model, or MBA, which suggests dopamine levels modulate how much noise is required for optimal cognitive performance. This theory indicates that the brains of people with learning differences like ADHD have lower levels of internal stimuli or noise.

"Taking this into consideration, adults and children with learning and thinking differences may be more likely to benefit from brown noise during work or study time, as the “under-stimulation” often associated with differences, like ADHD, may actually need this additional stimulation to focus better," Kahn says.

Research has shown that brown noise can also soothe conditions like tinnitus, or ringing in the ears, in certain individuals. Whereas the high frequencies of white noise exacerbated symptoms, brown noise helped to mask them.

The frequencies picked up in pink noise fall between white and brown noise and are also thought to aid in sleep. Some research has shown that listening to pink noise at bedtime induced more restful sleep. Because pink noise produces a deeper sound, some feel it's even more soothing than white noise.

"People with anxiety tend to be on high alert, and their bodies are always searching for evidence of danger to protect themselves," Kahn says. "The use of pink or brown noise may reduce their reactivity to those little sounds in their environment and support calming, sleep, or even concentration."

While the study findings around pink and brown noise have been promising, Kahn points out that most studies have consisted of small sample sizes. He urges people to practice caution when reading results.

How to Benefit

When seeking out pink and brown noise, Sarow reminds us that you can opt for natural sources like a water fountain, ocean waves, or heavy rain. And if those aren't available to you, there are always alternatives.

Music composer Nikhil Koparde works specifically in soothing sounds. Specializing in meditation music, binaural beats, and Solfeggio frequencies, he has been composing music for over 15 years.

"Sound frequency has been an area which has shown a constant upwards and positive growth," Koparde says. "We have finally figured out how to calculate which frequencies an individual responds well to, and which frequencies repel it."

Koparde is currently working on a project that will determine which frequencies are most important to the listener and then deliver personalized music in the hopes of improving sleep and reducing anxiety and depression.

"We put a combination of the right frequencies for that person and their state of mind into a music track," he says. "The idea is that all emotions have a state within the mind, and we use music and frequencies to activate or shut down particular states."

Koparde says the platform, called My Sound Technology, will eventually be white labeled and made available to places of healing like hospitals, psychology offices, and yoga studios, as well as mobile phone applications for personal use.

While public playlists may not be personalized to the listener's needs, plenty do exist for those interested in reaping the benefits of pink and brown noise. Apps, videos, and recordings are easy to find on YouTube and music streaming apps. Kahn recommends trying any program or app both with and without headphones to determine what's most comfortable and effective.

"Anyone with a smartphone will have access to dozens of free and low-cost options for all users, and trying out some apps that offer trials can provide ample opportunity to see how you like the tones in your own living, working, and study settings," he says.