Noise Colors: Which One Is Best for Sleep?

I frequently toss and turn at night. If a breeze whispers through the curtains, I’m up; if a car backfires, I’m wide awake. And, apparently, I’m not alone.

According to a 2022 survey conducted by Gallup and the mattress retailer Casper, a third of U.S. adults reported their sleep the previous night as either fair or poor — versus good, very good or excellent. This suggests that around 85 million of us, based on 2020 Census data, aren’t getting enough shuteye.

Across the internet, noise apps and machines are touted as the answer to this sleep deprivation — and also to a host of other health issues ranging from tinnitus to attention deficit hyperactivity disorder (ADHD). Read on to learn whether white, pink or brown noises are worth the hype.

Despite how frequently their benefits are touted, there’s not a lot of actual research on how noise colors impact things like sleep, anxiety and focus. A 2021 review of 38 different studies, carried out by researchers at the University of Pennsylvania, found little evidence that white noise improves sleep.

In fact, some of the studies from the review argue that continuously listening to sounds all night can be harmful. For one, some people may find that the added noise simply disrupts their sleep.

Another worry is that sleep is an important time for the brain; it must work to repair the body and improve our immune system during this time. If it must also analyze the calming sounds of white or pink noise, will the brain be working overtime?

And yet hundreds of millions of TikTok videos claim the sonic hues are a boon to our sleep schedules and overall mental health. Could this be a classic case of the placebo effect?

Well, one possible way white noise and other sounds can help you fall asleep is if you make them a staple in your nighttime routine. Whether or not this routine involves a noise machine, carrying out the same tasks prior to hitting the hay every night helps your brain recognize when it’s time to rest.

We’re creatures of habit, after all. Here are some other ways incorporating white noise or its analogues into your schedule might be helpful.

The way we perceive different types of noise depends on the frequency of their sound waves, or the number of times the sound waves repeat per second. Higher frequencies sound higher-pitched to the human ear, and lower frequencies sound lower-pitched.

Just as white light contains every color of the rainbow, white noise contains every frequency that we can hear — from around 20 to 20,000 hertz. But because all these frequencies are played in fast, random succession, our brains combine them in a Frankenstein-esque way that ultimately mimics TV or radio static.

Perhaps unsurprisingly, white noise is the most studied of all the different colors. And various studies have shown that it’s a great way to manage distractions.

Our brains are better at detecting changes in our environment if there’s a low level of interfering background information. You won’t get your best reading done while, say, a fire alarm is blaring.

Adding white noise to the mix can help mask smaller distracting sounds by making them seem less significant to your brain. A 2021 study published in Sleep Medicine tested this technique in bustling New York City and found that listening to white noise at night indeed helped participants who struggled to fall asleep due to outside noise.

For this same reason, white noise has also proven useful for those with tinnitus, ADHD and reading disabilities.

Of course, white noise isn’t perfect. Because our ears are naturally attuned to higher frequencies, many people find it to be too high-pitched for their taste. If that rings true for you, read on for some alternatives.

Pink noise is considered a more balanced listening experience compared to white noise because it dampens the volume of the higher frequencies on the sound spectrum. Basically, it accounts for our natural sensitivity to those frequencies. 

As a result, pink noise mimics the calming sound of steady rainfall — or even the sounds inside a womb.

In 2012, a team of researchers based in China analyzed the brain waves of 40 sleeping subjects while they listened to pink noise. Compared to those who slept without it, the researchers found evidence of deeper sleep, less complex brain waves and fewer responses to potential sleep disruptions.

Other studies have shown it can be useful for relaxation and tinnitus, and various researchers have also experimented with using pink noise to help our brains better catalog memories during deep sleep — though more research is necessary to confirm whether this is the case for all or even most people.

Read More: Research Shows Promising Effects of Music on Brain Power

Brown noise — technically named Brownian noise after the Scottish botanist who discovered the random movements characteristic of Brownian motion — takes us one step beyond pink nose. This pattern further dampens higher frequencies to create a deeper, rumbling sound that mimics distant thunder, a waterfall or the inside of a plane cabin while in flight.

Similar to white and pink noise, brown noise is useful for masking distracting sounds. Opt for brown noise, however, if those sounds are a bit lower in pitch.

In a 2018 study published in Frontiers in Psychology, brown noise was also shown to support the transition into REM sleep for some. Other research additionally points to positive impacts on psychomotor skills, executive function, working memory and tinnitus.

A common myth warns us of the infamous brown note, a sound frequency so low it can cause spontaneous bowel movements as it rumbles through the human body. While that may sound like a convenient alternative to incorporating more fiber in your diet, the brown note is in fact nothing more than a legend.

White, pink and brown noises are the most commonly known and studied, but there are plenty of other sonic hues.

Violet noise, sometimes called differentiated white noise, plays high frequencies at a higher volume than brown noise but also makes a hissing sound.

Blue noise is reminiscent of a hissing garden hose and is useful for dithering — aka adding low levels of noise to audio to reduce distortion when converting to lower resolutions. 

Green noise concentrates on mid-range frequencies around 500 Hz, like the sounds you might hear in nature, earning it the nickname, “the noise of the world.”

Perhaps the most unusual is orange noise, which uses all the frequencies of the spectrum except for those that are considered “in-tune.”

Or if you’re gung-ho about white noise, you might give gray noise a chance; it sounds a tad smoother because it’s calibrated so that your ears hear every frequency at the same volume.

Ultimately, you're better off choosing whichever noise simply appeals most to you. And, of course, if you’re really not a fan of any of the above, try black noise — better known as silence!

Read More: Awkward Silences: Maybe It's Time to Stop Avoiding Them and Start Embracing Them