Chromatic Chaos: Like a Rainbow, Noises Can Be Colorful

Find white noise more irritating than soothing? Staff Writer Pho Vu ’23 breaks down the ambient noise spectrum and each hue’s benefits for sleep, wellness, and productivity.

Chromatic Chaos: Like a Rainbow, Noises Can Be Colorful
The different “colors” of noise. Graphic courtesy of Nina Aagaard ’26.

Ask a random group of people how they handle procrastination.

Everyone will have a different answer for dealing with distractions, but many have likely turned to the powerful help of background sounds at least once — and white noise is one of the most popular options. YouTube videos (especially those with glowing brain-related thumbnails) featuring white noise have garnered millions of views from those looking to improve their concentration while studying.

But have you ever felt that, despite working its magic on everyone else’s focusing abilities, white noise is just not meant for you? Well, the good news is that you are not the only one. In 2022, by setting two different conditions of white noise in a study involving 39 participants, University of Southern California researchers found that while white noise improved some portions — sustained attention and creativity — of cognitive performance, it failed to show any great changes in selective attention, inhibition, and working memory. The results speak to the fact that, because each and every brain has different needs, not everyone will benefit from white noise.

Yet, there’s still room for optimism. Contrary to popular belief, white noise isn’t the only kind of brain-optimizing noise. Categorized by colors, these under-the-radar noises offer many advantages.

White Noise
For starters, white noise is perhaps the most well-known “color” of noise. White noise is the sound of static you hear on a radio or TV when there’s no signal, or the humming of the AC the moment you activate it. Similar to the color white, an amalgam of pigments of all visible lights, white noise contains equal amounts of all frequencies in the audible range. This makes it a useful tool for masking other sounds, such as tinnitus or outside noise that might be keeping you awake at night.

In the study mentioned above, however, a heightened level of white noise can actually do more harm than good. For example, 65 decibels of white noise was reported to solely improve working memory and raise stress.

Pink Noise
Pink noise is similar to white noise but has a different flat spectral density: Instead of having equal energy across all frequencies, pink noise has more energy in the lower frequencies and less in the higher frequencies. This gives it a more natural, soothing sound often compared to falling rain or ocean waves. Pink noise is widely implemented in relaxation and meditation apps (one of them is Calm), as well as in sound systems for music and film. The sounds of rustling leaves or howling winds can give you an approximation. In case you need more, your heartbeat’s rhythm is actually one of the strong pink noise-producing sources. Proven to reduce brain waves and improve memory in older adults in a 2017 study, pink noise is a strong aid for sleep stability.

Brown(ian) and Red Noise
For a moment, disregard what you learn about colors: Within this auditory subject, brown and red noise are the same thing. The “brown” in brown noises does not derive from a color name but from scientist Robert Brown who created “Brownian motion” from erratic sounds. Sometimes referred to as 1/f noise, this noise is a deeper, more rumbling sound than white or pink noise. The noise has even more energy in the lower frequencies than pink noise, which gives it a bass-heavy quality. Bearing high resemblance to the mind’s resting state, listening to brown noise easily allows people to enter their relaxation zone. Brown noise is extremely helpful for your sleep and focus, and it is sometimes used in music production to create a sense of depth and warmth.

Make sure not to confuse this brown noise with another mythical brown noise (or brown note) that is believed to make listeners defecate uncontrollably.

Blue and Purple Noise
Brown and red noise may have a twin with perfectly contrasting personalities, and that is blue and purple noise. Unlike brown and red noise, blue and purple noises are two distinct noises. Their abilities to treat tinnitus and mask sounds unite them. Another thing that separates them from 1/f noise (with indirect proportional relationship to frequencies) is their direct proportional relationship to the changing frequencies. Additionally, blue noise is the sound of a hair spray and actively contributes to the computer graphics field with its production of good-quality visual resolution.

Gray Noise
Gray noise does not exist in nature. Programmed specifically to help tinnitus sufferers sleep better during noise therapy, gray noise contains the same amount of loudness throughout and is audible to humans’ ears.

Orange Noise
If orange noise were a vocalist, it would be the kind that sings everything out of tune. It is stripped of several bands, and the noise possessing many “sour” notes is the result that follows.

Green Noise
If you often find yourself productive through reconnecting with nature, there is a high chance you will click with this nature-based noise at first listen. Beach waves and waterfalls are two emerging examples of this environmental sound. If all you desire is a peaceful sleep in the forest, definitely go give this one a try.

Black Noise
Paul Simon wrote “The Sound of Silence” in 1964, and the title of this legendary song is perfect to describe this type of noise. Unlike other listed noises, black noise consists of absolute silence or near silence with just a bit of random noise or sounds beyond the limit of human hearing. With zero frequencies, black noise may be preferred by people who want little to no noise at bedtime.

In daily life, noise is usually perceived as distracting. However, like most things that have two sides, noises can be “noice.”

It’s time you hop on this noise exploration journey and find out the ultimate one for your next study or sleep sesh!