Sound Science

White vs Brown vs Pink Noise: The Complete Comparison

Updated July 4, 2026

Every noise colour explained — frequency profiles, what each does for sleep, focus and masking, and which to pick for your goal.

Why "Colours" of Noise?

The "colour" terminology borrows from optical physics: just as white light contains every visible wavelength, white noise contains every audible frequency at equal intensity. Different colours = different frequency weightings.

Three colours dominate the sleep & focus conversation: white, pink and brown. They differ not in what frequencies are present, but in how loud each frequency is relative to the others.

Choosing well matters: white noise can feel fatiguing over hours; brown noise can feel muffled when you actually want masking. The right colour depends on your goal, the room, and your own ears.

0 dB/octwhite noise: flat power across all frequencies
−3 dB/octpink noise: equal power per octave — gentler on ears
−6 dB/octbrown noise: low-end heavy, deep and rumbly

Quick Reference Table

White vs pink vs brown noise compared — spectrum, sound character and best use case.
Colour Sound Spectrum Best for Avoid if
White Bright hiss, like untuned TV static Flat (equal energy) Masking speech, ADHD focus, baby sleep You find high frequencies fatiguing
Pink Soft waterfall, balanced rain −3 dB/oct (equal per octave) Deep sleep, memory consolidation, natural feel You need strong low-end masking
Brown Deep rumble, distant thunder, low waterfall −6 dB/oct (very bass-heavy) Long focus sessions, low-frequency masking, anxiety You're masking high-pitched sounds (alarms, voices)
Grey Perceptually flat across human hearing Psychoacoustically equal-loudness Tinnitus retraining, hearing tests You want a single dominant texture
Blue / Violet Sharp, hissy, high-pitched +3 / +6 dB/oct (treble-heavy) Audio engineering tests, tinnitus therapy Sleep — too harsh for relaxation
Black Silence with sparse events; very deep drone Mostly empty / sub-bass only Light sleepers who dislike continuous sound You need consistent masking

When to Use Each Colour

⚪

White noise

Reach for white noise to mask sharp, intermittent sounds (chatty office, snoring partner). Strong evidence for use in NICU and infant sleep. Can feel hissy after an hour.

🌸

Pink noise

Closest to natural soundscapes (rain, wind). Papalambros et al. (2017) found pink noise played in phase with slow-wave sleep enhanced memory in older adults. A safe default for most people.

🟤

Brown noise

The deep, warm choice. Popular among ADHD adults for long focus sessions. Excellent for masking low traffic rumble and air-handling units. Less effective against high-frequency disturbances.

🔘

Grey noise

Engineered to sound equally loud at every frequency to the human ear. Used clinically in tinnitus retraining therapy. Less common in consumer apps.

🟣

Violet / blue noise

Treble-heavy and harsh. Niche uses: tinnitus masking at specific high frequencies, audio engineering test signals. Rarely used for sleep.

⚫

Black noise

An informal term — sometimes meaning near-silence, sometimes ultra-low-frequency drone. Useful for light sleepers who find any audible noise distracting but still want a "presence" in the room.

About the Author

ASMR Sanctuary Wellness Team — a small editorial group reviewing peer-reviewed research on ambient sound, sleep science, psychoacoustics and contemplative practice. Every article is reviewed for accuracy against current PubMed-indexed literature. Last reviewed:

Sources & Further Reading

This article is for educational purposes only and is not medical advice. Always consult a qualified healthcare professional for personal concerns.

Frequently Asked Questions

What is the difference between white, pink, and brown noise?
White noise has equal energy across all frequencies — it sounds harsh and hiss-like. Pink noise has energy that decreases by 3 dB per octave — warmer, resembling rainfall. Brown (red) noise has energy decreasing at 6 dB per octave — deeper, resembling strong wind or river flow. Each colour occupies a different position in the frequency spectrum.
Which noise colour is best for sleep?
Brown noise is preferred by most people for sleep due to its warm, deep character that's easiest to habituate to. Pink noise has the strongest research support — a 2017 Frontiers in Human Neuroscience study showed it significantly enhanced slow-wave sleep and memory consolidation. White noise works well for masking high-frequency disruptions but can feel harsh over extended periods.
Why is it called "white" noise?
The term is borrowed from optics: white light contains all visible wavelengths equally. White noise contains all audible frequencies in equal measure. By the same analogy, pink noise (named after pink light, which has more low-frequency energy) and red/brown noise (named after red light) describe their frequency spectrum distributions.
Can noise colours help with tinnitus?
Yes. White, pink, and brown noise are all used in tinnitus sound therapy. The goal is acoustic masking — providing broadband background sound that makes tinnitus less perceptible. Many people with tinnitus find brown noise most comfortable for long-term masking, as its absence of harsh high frequencies reduces ear fatigue.
Is brown noise actually called "Brownian noise"?
Yes. Brown noise is technically Brownian noise, named after Robert Brown, who described Brownian motion (random particle movement). The frequency spectrum of Brownian noise follows the same mathematical relationship as Brownian motion — energy decreasing by 6 dB per octave as frequency doubles. "Brown" in the colour sense is a fortunate coincidence, not the origin.
Does pink noise actually improve memory consolidation?
A 2017 Frontiers in Human Neuroscience study (Papalambros et al., 2017) found that pink noise synchronised to slow brain oscillations during NREM sleep significantly improved word recall in older adults compared to sham conditions. Replication studies are ongoing. The mechanism appears to involve acoustic phase-locking with the slow oscillations that drive memory consolidation during deep sleep.
What is green noise and is it a recognised category?
"Green" noise is not a formally defined acoustic category — it's a marketing term typically used to describe natural soundscapes (typically pink-noise-like spectra) or mid-frequency-heavy variations. "Blue" and "violet" noise (increasing energy with frequency) are technically defined but not commonly used for wellness purposes.
Which noise is best for ADHD focus?
Community experience and stochastic resonance theory suggest brown noise works best for many people with ADHD, particularly for deep work. Its low-frequency emphasis occupies the brain's distractibility monitoring system without the harsh high frequencies that can cause agitation. Multiple online surveys rank brown noise as the most effective ADHD focus sound.
At what volume should I use noise for sleep or focus?
WHO guidelines recommend nighttime noise below 40 dB at the ear. For active use (focus), 50–70 dB is typical. A practical rule: set noise at a level where you can hear normal speech in the room but it feels like background — about the volume of a quiet conversation. Too loud reduces effectiveness and risks long-term hearing effects.
Can I mix different noise colours together?
Yes, and many people find custom blends more effective than pure noise colours. Common blends: pink + brown (adds warmth and depth), white + pink (better masking with less harshness), rain + brown (natural + electronic depth). ASMR Sanctuary synthesises all three noise types simultaneously — use the mixer to blend to taste.

Try Every Colour

All noise colours are available free — no sign-up, no app.

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