Brown Noise vs White Noise vs Pink Noise: What's the Difference?
White noise has equal energy at every frequency, so it sounds bright and hissy. Pink noise loses energy as pitch rises (3 dB less per octave), so it sounds more balanced, like steady rain. Brown noise drops faster (6 dB per octave), so it sounds deep and rumbling, like a strong waterfall or distant thunder. All three can cover up background sound, and which one works best is mostly personal preference.
What each color of noise actually is
The "colors" are names for how a sound's energy is spread across the frequency range. Think of the spectrum as a row of equalizer sliders from bass on the left to treble on the right.
| Noise | Energy slope | What it sounds like | Common comparison |
|---|---|---|---|
| White | Flat (equal energy per Hz) | Bright, hissy, a lot of treble | TV static, a running fan with the grille off |
| Pink | Falls 3 dB per octave | Balanced, softer than white | Steady rain, wind in leaves |
| Brown (red) | Falls 6 dB per octave | Deep, rumbling, little treble | Waterfall, heavy surf, distant thunder |
"Equal energy per Hz" sounds like it should be even, but human hearing works in octaves, not in fixed steps of hertz. There are far more hertz in the top octave (10 to 20 kHz) than in the bottom one (20 to 40 Hz), so white noise ends up sounding top heavy. Pink noise corrects for that by giving each octave roughly the same energy, which is why it feels more natural.
Brown noise is named after Robert Brown and Brownian motion, not the color. It is also called red noise, and you will see the two names used for the same thing.
How they sound different in practice
Play the three one after another at the same volume and the difference is obvious.
- White noise is sharp. The high frequencies sit right where speech consonants live (roughly 2 to 8 kHz), which is why it is good at masking voices and why some people find it fatiguing.
- Pink noise is smoother. Most people describe it as the easiest of the three to listen to for a long time.
- Brown noise is mostly low end. It feels more like a vibration than a sound, and on small laptop or phone speakers it can seem almost silent, because those speakers barely reproduce below 100 Hz. Headphones or a decent speaker make a big difference.
What people use them for
People use steady noise for three main reasons: sleep, focus and masking. The evidence is real but modest. Small studies suggest some people fall asleep faster or concentrate better with noise, and some find it makes no difference. Treat it as something to try rather than a guaranteed fix.
Sleep
Steady sound covers sudden noises such as traffic, doors and neighbors, which can otherwise wake you. Pink and brown noise are the usual picks because they are gentle. White noise works too, especially if the sounds you want to hide are high pitched. If you prefer a fan-like sound, white noise is the closest match.
Focus and studying
Open offices and shared homes are full of speech, and speech is hard to ignore. White or pink noise at a low volume can blur conversations into the background. Some people with ADHD report that brown noise helps them settle, but the research here is thin and mixed, so judge by how it feels for you.
Tinnitus
A constant sound can make ringing in the ears less noticeable, which is why sound therapy is a common part of tinnitus management. Pink and brown noise are popular because they are less harsh than white. Keep the noise quieter than the tinnitus rather than trying to drown it out, and see an audiologist if the ringing is new, only in one ear, or comes with hearing loss or dizziness.
Babies
White-noise machines are widely used for infants, but loudness matters. Pediatric guidance advises keeping them well below the level that could harm hearing and placing the device across the room rather than in the crib. See the safe levels section below.
How loud should it be?
Quieter than you think. For sleep and focus, the noise should sit just above the background you are hiding, around the level of a quiet conversation (50 to 60 dB). Louder does not mask better, it only adds strain.
Hearing guidance gives a useful ceiling. NIOSH recommends no more than 85 dBA for 8 hours, and every 3 dB above that halves the safe time. At 88 dBA it is 4 hours, at 91 dBA 2 hours, and so on. All-night noise should be nowhere near that. If you are not sure how loud your setup is, measure it with the sound meter and keep a sleeping environment closer to 50 dB than 85.
A few practical rules:
- Start with the volume lower than you expect and raise it only until the distracting sounds fade.
- Use a speaker across the room instead of earbuds in bed, which sit very close to the eardrum and can be uncomfortable.
- If you wake with ears that feel full, or ringing that is worse than usual, turn it down and talk to a doctor.
Which one should you pick?
Try them in this order and keep whichever you stop noticing.
- Pink noise is the safest default. It sounds natural and suits most people.
- Brown noise if pink still feels thin or harsh and you have speakers or headphones that can play bass.
- White noise if you need to hide high-pitched sounds, or you like the fan-like hiss.
You do not need to buy a machine to compare them. The white noise generator plays white, pink and brown noise in your browser, so you can switch between them in a few seconds and see which one you can ignore best. For more on frequency and pitch, the human hearing range guide explains why low rumbles feel so different from high hiss.
Why brown noise sounds "quiet" on some devices
If brown noise seems weak or tinny, the problem is almost always the speaker. Brown noise puts most of its energy below 200 Hz, and phone, laptop and small Bluetooth speakers roll off sharply in that range. The sound you hear is then just the faint upper part. Switching to headphones usually fixes it. Turning the volume up to compensate is the wrong move: you will reach a loud level before the deep part appears.
Everything stays on your device
The noise is generated in your browser as you listen, so nothing is uploaded or recorded.