White noise vs brown noise comes down to two things: what you need to block out, and what your ears find comfortable. White noise is better at covering sudden, sharp sounds like a barking dog or a slammed door. Brown noise is deeper and softer, and many people find it more relaxing for sleep. Pink noise sits in between.
This guide explains how the colors of noise differ, what the research does and does not show, and how loud a sound machine should be. It is based on published studies and noise guidelines, not on personal testing.
In this article
- White noise: strong masking, but a bright sound
- White noise vs brown noise: decoding the colors of sound
- Brown noise: the deep, soft option
- The pink noise middle ground
- Hardware vs. apps: the loop problem
- Safe volumes: how loud is too loud
- How to build your sound environment
- Common questions about noise colors
- Finding the quiet
- Sources
At a Glance
- White noise: a bright hiss. Best for covering sharp, sudden noises.
- Pink noise: softer, like steady rain. A good middle ground.
- Brown noise: a deep rumble. Many people find it the most relaxing; it covers low sounds like traffic best.
- Volume: keep it as low as works, at most about 50 dB at your pillow, and keep the machine away from your head.
White noise: strong masking, but a bright sound
White noise spreads its energy evenly across every frequency people can hear, from about 20 Hz to 20,000 Hz. Because so much of that range is high-pitched, and our ears are most sensitive in the upper-middle range, white noise sounds bright and hissy, like radio static.
That brightness is also its strength. A sharp sound, such as a dog barking or a door slamming, stands out much less against a steady sound that covers the same pitches. The downside is comfort: some people find the hiss tiring or irritating, especially at higher volumes.
Myth vs fact
Myth: All noise machines make the same sound. Fact: A machine with a real fan makes a soft, lower-pitched rushing sound, while a digital speaker can play anything from bright white noise to deep brown noise.
White noise vs brown noise: decoding the colors of sound
The “color” of a noise describes how its energy is spread across low and high frequencies. White noise is flat. Pink noise has less energy as the pitch rises. Brown noise drops off even more steeply, so most of its energy is in the low, bass range.
| Noise color | How the energy is spread | What it sounds like | Often used for |
|---|---|---|---|
| White | Equal at all frequencies | Radio static, a hissing kettle | Covering sharp, sudden noises |
| Pink | Falls as pitch rises (1/f) | Steady rain, wind in leaves | Sleep, a calmer background sound |
| Brown | Falls steeply as pitch rises (1/f²) | A low roar, distant thunder, an airplane cabin | Relaxing, covering low rumbles like traffic |
If you are sensitive to high-pitched sounds, white noise is the color most likely to bother you. Try pink or brown first.
Brown noise: the deep, soft option
Brown noise (also called red or Brownian noise) takes its name from Brownian motion, the random movement of particles first described by the botanist Robert Brown, not from the color. It puts most of its energy into low frequencies, so instead of a hiss you hear a deep, steady roar.
Many people say brown noise helps them relax, fall asleep or focus, and it has become popular online, including among people with ADHD. The research has not caught up: most studies of noise and attention used white noise, and there is little direct research on brown noise and sleep. Brown noise is also weaker at covering high-pitched sounds, such as voices or a crying baby.
Try this tonight
- In a free noise app, play white noise for 5 minutes at a low volume.
- Then pink noise for 5 minutes, then brown noise for 5 minutes.
- Keep the one that covers your problem sound and still feels comfortable.
The pink noise middle ground
Pink noise reduces the high frequencies that make white noise sound harsh, but keeps more of them than brown noise. It sounds like steady rain or wind, and it is a common choice for people who find white noise too sharp but brown noise too heavy.
Pink noise also has the most interesting research. In small lab studies, short bursts of pink noise played in time with a person’s deep-sleep brain waves strengthened those waves and, in some studies, improved memory the next day. Those studies used special equipment that tracks brain waves, which is very different from a machine playing all night, so the results do not show that an ordinary pink-noise machine improves deep sleep.
Hardware vs. apps: the loop problem
Many noise apps play a short recording on repeat. Some people notice the point where the loop restarts, and a change in the sound is exactly the kind of thing that can disturb light sleep. When you choose an app or machine, look for one that generates the noise continuously or uses long recordings.
Fan-based machines, such as the Yogasleep Dohm, make their sound with a real fan inside a housing, so there is no loop. The sound is soft and fairly low-pitched, but you cannot change its color. Digital machines are speakers: they offer several colors and volume steps, and the better ones do not loop. Small phone speakers cannot play deep bass, so brown noise from a phone often sounds thinner than it should.
Safe volumes: how loud is too loud
More noise does not mean better sleep. The World Health Organization’s Guidelines for Community Noise (1999) recommend that background noise in a bedroom stay below about 30 dB, with single noise events under 45 dB. A sound machine adds to that, so the aim is the lowest level that still covers the sound that bothers you.
Very loud all-night sound is a hearing risk. The US National Institute for Occupational Safety and Health (NIOSH) sets 85 dB averaged over eight hours as its limit for workplace noise. A machine running near that level for a whole night gets close to it. A 2014 study in Pediatrics tested 14 infant sleep machines at full volume: measured 30 cm away, three of them went above 85 dB.
Masking works by making a disturbing sound stand out less, not by drowning it. A car horn that jumps from a quiet room is more likely to wake you than the same horn against a steady background. For most people, about 50 dB or less at the pillow is enough.
When to see a doctor
If you need very loud noise to sleep, if ordinary sounds feel painful, or if you have ringing in your ears that does not go away, see a doctor or an audiologist. Sensitivity to sound (hyperacusis) and tinnitus can be assessed and treated.
How to build your sound environment
- Name the problem sound. High-pitched sounds (voices, a barking dog) are covered best by white or pink noise. Low sounds (traffic, a neighbor’s music) are covered best by brown noise.
- Test the colors for free with an app, 10 minutes each, at a low volume.
- Choose a machine or app that does not loop, or a fan-based machine.
- Measure the volume. Use a free decibel meter app with the phone on your pillow, and stay at about 50 dB or less.
- Place it well. Keep it away from your head, ideally between you and the noise, such as near the door or window.
Common questions about noise colors
Is brown noise better for you than white noise?
Neither is better for everyone. Brown noise is softer and many people find it more relaxing; white noise is better at covering sharp, high-pitched sounds. Choose by comfort and by the sound you need to block.
What is brown noise best for?
Covering low rumbles like traffic, and as a calm background sound for people who find white noise harsh. Research on brown noise specifically is still limited.
Does the speaker change how the noise sounds?
Yes. Small speakers cannot reproduce deep bass, so brown noise from a phone can sound thin. A speaker with a larger driver plays it more faithfully.
Can white noise help with tinnitus?
Sound therapy can make ringing in the ears less noticeable, which helps some people sleep. It does not cure tinnitus. An audiologist can suggest the right kind of sound and volume.
Finding the quiet
Start with the sound you need to block, try the three colors at a low volume, and keep the one that is both effective and comfortable. Then keep the volume modest and the machine away from your head. A good background sound should fade into the background, not become the next thing that keeps you awake.
If the sound keeping you awake is a partner’s snoring, our guide to earplugs for a snoring partner covers what helps. If you would rather not sleep with sound at all, see how haptic sleep devices compare with sound machines.
Sources
- World Health Organization. Guidelines for Community Noise, 1999.
- NIOSH. Occupational noise exposure: recommended exposure limit of 85 dBA over 8 hours.
- Hugh SC, et al. Infant sleep machines and hazardous sound pressure levels. Pediatrics, 2014.
- Ngo HV, et al. Auditory closed-loop stimulation of the sleep slow oscillation enhances memory. Neuron, 2013.
This article is general information, not medical advice. See our medical disclaimer.
[…] daytime is noisy. Earplugs or a steady sound machine can help. Our guide to white noise vs brown noise explains the […]
[…] earplugs, or a steady background sound. See white noise vs brown noise, or haptic sleep devices if you prefer gentle vibration to sound. If a partner’s snoring is […]