ST-90 · SIDE N · THE NOISE SPECTRUM
Noise Colors, Side by Side.
Every noise color is the same random static with a different tilt — brighter, balanced, or deeper. Play white, pink and brown back to back below, then use the table to pick the right one for sleep, focus, ADHD or masking. Ten seconds each is all the test takes.
14-DAY FREE TRIAL · PAY ONCE · NO SUBSCRIPTION · OFFLINE
01 — LISTEN
The ten-second test.
Previews are 20-second clips. In NoiseTape every sound is a seamless, gap-free loop tuned for 8-hour sessions — keep listening in the app.
- White Noise
- Pink Noise
- Brown Noise
02 — THE SPECTRUM
One family, five colors.
The color names borrow from light. White noise spreads equal energy across every audible frequency, the way white light contains every wavelength — played aloud it reads as bright hiss. Tilt the energy downward by 3 dB per octave and you get pink noise, the balance point that most resembles steady rain. Tilt it 6 dB and you reach brown noise, a deep rumble like a waterfall or an airliner cabin. Keep going past the familiar three and you meet green noise — a newer nickname for noise centered on the middle frequencies, essentially nature's band — and blue and violet noise, which tilt the opposite way and are mostly used in hearing research, not for sleep.
| Color | Spectrum tilt | Sounds like | Best for |
|---|---|---|---|
| White | Flat — equal energy everywhere | TV static, radio hiss | Maximum masking of voices, clatter and sudden noise |
| Pink | −3 dB/octave | Steady rain, wind in leaves | Sleep, studying — coverage without the harsh hiss |
| Brown | −6 dB/octave | Waterfall, airliner cabin, distant surf | Deep sleep, ADHD focus, sensitive ears |
| Green | Mid-frequency band, roughly 500 Hz centered | Rushing river, steady rainfall on grass | A natural-feeling middle ground; try our river and waterfall loops |
| Blue / Violet | Rises toward high frequencies | Fine, sharp hiss | Hearing research and some tinnitus therapy — rarely for sleep |
The honest answer to "which is best" is whichever one your brain stops noticing first. Masking only works when the sound itself doesn't demand attention, and that threshold is personal: side sleepers next to a snorer often need white's full coverage, most people relax fastest into pink, and many ADHD listeners swear by brown's weight. Play each loop above at the volume you'd actually sleep at and pick the one that disappears. In NoiseTape all three are seamless, gap-free loops — plus 110 real recordings if you'd rather have a waterfall do brown noise's job — with a sleep timer that fades everything out once you're gone.
03 — FAQ
Noise color questions, answered.
What are noise colors?
Noise colors are nicknames for how random noise distributes its energy across frequencies, borrowed from the physics of light. White noise is flat — equal energy at every frequency. Pink noise loses 3 dB per octave as frequency rises, brown noise loses 6 dB, so each sounds progressively deeper. Green, blue and violet describe other tilts. The sound source is the same random signal; only the tilt — and therefore the character — changes.
Which noise color is best for sleep?
There is no universal winner — the best masking sound is the one your brain ignores fastest. Pink noise is the most common recommendation because it covers disturbances without white noise's harsh top end, and small studies associate it with deeper slow-wave sleep. Brown noise feels calmer still to many people, especially sensitive ears. The practical method: play each for ten seconds at bedtime volume and keep the one you stop hearing first.
What is green noise, and is it real?
Green noise is a looser, newer term for noise concentrated around the middle of the audible spectrum — roughly where rushing water and steady rain live. Unlike white, pink and brown, it has no strict engineering definition, but the sound it describes is real enough: if green noise appeals to you, a river, waterfall or steady-rain recording gives you the same character with natural texture. NoiseTape includes all of these as seamless loops.
Why do people with ADHD prefer brown noise?
The popular theory is that steady broadband noise gives an under-stimulated brain a constant, undemanding signal that quiets the search for stimulation — and brown noise delivers that signal without the fatiguing high-frequency hiss of white noise, so it stays comfortable for hours. The research is early and individual results vary, but the pattern is common enough that brown noise has become the community's default. Try brown against pink above; the right one is the one you forget is playing.
See also: white noise for sleep & focus · pink noise for deeper sleep · brown noise for sleep & focus · the full 113-sound library