Brown noise for sleep

A deep, steady rumble with the hiss taken out. Here's what brown noise actually is, who tends to like it, and how to set it up so it lasts the whole night.

What brown noise is

Brown noise is random sound whose energy falls off steeply as the pitch rises: each octave up carries about a quarter of the power of the one below it (a drop of roughly 6 dB per octave). The result is a sound that lives mostly in the low end. Think of the roar of a distant waterfall, heavy surf heard from inside a house, or the steady hum in an airplane cabin.

It gets its name from Robert Brown, the botanist who described Brownian motion, not from the color. You will also see it called red noise or Brownian noise. Mathematically it is what you get when you add up white noise over time, which is why it sounds smooth and rolling rather than hissy.

Press play on the tile above to hear it. If it sounds thin, that is your speaker, not the noise: most of brown noise sits below what a phone speaker can reproduce well.

Why people like it for sleep

The idea behind any steady noise at night is masking. Your brain notices changes in sound far more than steady sound. A car door at 2 a.m. stands out against silence. Against a constant background, the same sound is a smaller jump, so it is less likely to pull you out of sleep.

Brown noise does this with a sound most people find softer than white noise. There is less of the high-frequency hiss that some listeners describe as harsh or "static-like". It also happens to overlap well with the low, rumbling noises that tend to bother people at night: traffic, a neighbor's TV through the wall, an upstairs washing machine, a partner's snoring.

What the evidence does not say is just as important. A 2021 systematic review in Sleep Medicine Reviews looked at studies of continuous noise used as a sleep aid and judged the overall quality of evidence to be very low, with mixed results. There is almost no research on brown noise specifically. So treat brown noise as a comfort and masking tool that many people prefer, not as something proven to change your sleep.

Who brown noise tends to suit

Brown noise is usually a good first try if:

• You find white noise too bright. If white noise sounds like a hissing radiator to you, brown noise removes most of that.
• The noise that wakes you is low. Traffic rumble, footsteps upstairs and bass from next door sit in the same range brown noise covers.
• You like the feeling of a "blanket" of sound. Many people describe brown noise as cozy or enclosing, like being inside a car in the rain.

It may not be the best pick if the sounds that bother you are high and sharp, like voices, a dog barking or a squeaky door. For those, brighter sounds like white or pink noise often mask better. Our white vs pink vs brown noise guide compares all of them side by side.

How to set it up for a full night

1. Start quieter than you think. Turn the volume down until you can barely hear it, then raise it a notch at a time until the sounds that bother you blend in. You want it low enough that you could still hear someone speak to you in a normal voice.

2. Use a speaker that can play bass. A phone speaker loses most of brown noise's low end. A small Bluetooth speaker or a smart speaker on the nightstand will sound fuller at a lower volume, which is better for you.

3. Put some distance between you and the sound. Arm's length or farther is a good rule. Don't fall asleep with the phone under your pillow.

4. Decide: all night or a fade-out. Some people wake when sound suddenly stops. If that's you, leave it playing until morning or use a timer that fades out slowly. In the Sleep Better app you can let it run all night and fade out by your wake-up time.

5. Give it a few nights. A new sound can feel noticeable at first. Most people stop hearing a steady background after a little while, the same way you stop noticing a fridge hum.

For the practical side of keeping sound going until morning, without a video that stops when your phone locks, see our guide to playing sleep sounds all night with the screen off.

Brown noise vs. similar sounds

If brown noise feels too heavy or muffled, pink noise is the usual next step. If you want something that sounds less like a machine, try rain: our rain sounds for sleep page covers soft rain, heavy rain and thunder.

Mixing brown noise with other sounds

Brown noise also works well underneath other sounds. A low layer of brown noise under rain fills in the gaps between drops so the overall sound is steadier. Some people also like a quiet brainwave (binaural) beat beneath it; those need headphones to work, because each ear gets a slightly different tone.

In the app you can blend a beat under any sound with a slider. Keep the mix simple: one or two layers is usually enough, and more layers makes it easier for one element to catch your attention.

Common questions people search

"Brown noise black screen." People look for this because they want the sound without a bright screen. You don't need a video for that: an audio app that keeps playing when the phone is locked gives you a fully dark room. We explain the options, including the free ones built into iPhone, in the all-night setup guide.

"Brown noise for focus." You'll see a lot of online claims about brown noise and concentration. Some people do find it helpful as a background for work, but the research is thin, and this page is about sleep. If you want something for daytime, try it at a low volume and see.

"Brown noise for babies." Infant sleep is a different topic with its own safety advice. A 2014 Pediatrics study of infant sleep machines found every one tested could exceed 50 dBA at 30 cm at full volume, the limit recommended for hospital nurseries. If you use any sound for a baby, keep it quiet, far from the crib, and follow your pediatrician's advice.

This page is general information about sound and sleep habits, not medical advice. If poor sleep is affecting your days, talk to a doctor or a sleep specialist.