Brown Noise vs Pink Noise vs White Noise: What's the Difference?

White noise, pink noise, and brown noise are not colors. They are three types of random sound with different frequency distributions. The names come from an analogy with light: white light contains all visible frequencies equally, just as white noise contains all audible frequencies equally.

But the three types sound very different, and each one is better suited for different purposes. Here is what each one actually is, what it sounds like, and when to use it.

White noise: equal energy at every frequency

White noise has the same energy (amplitude) at every frequency from 20 Hz to 20,000 Hz. If you plot it on a spectrum analyzer, the line is flat.

To human ears, white noise sounds hissy and bright — like an untuned FM radio or static on a television. This is because human hearing is more sensitive to mid-range and high frequencies. Since white noise has equal energy at all frequencies, the high frequencies dominate what you actually perceive.

Technical specs:

Frequency distribution: Flat (equal energy per Hz)
Sounds like: Radio static, television snow
Perceived character: Hissy, bright, harsh

Best for: Masking high-frequency sounds like typing, conversations, or street noise. White noise is the most effective at drowning out speech because it covers the exact frequency range where human voice sits (300–3,000 Hz).

Worst for: Sleep, if you find it too harsh. Some people find white noise fatiguing over long periods.

Pink noise: equal energy per octave

Pink noise has the same energy per octave, not per Hz. This means it loses about 3 dB of energy for every doubling of frequency. Low frequencies are louder relative to high frequencies.

To human ears, pink noise sounds balanced and natural — like steady rain, wind through trees, or a waterfall. Most natural sounds have a 1/f (pink) frequency spectrum, which is why pink noise often feels more comfortable than white noise.

Technical specs:

Frequency distribution: 1/f (loses 3 dB per octave)
Sounds like: Steady rain, wind, waterfall
Perceived character: Balanced, natural, warm

Best for: Sleep, meditation, and focus. Pink noise is the most studied of the three for sleep improvement. A 2017 study in Frontiers in Human Neuroscience found that pink noise increased deep sleep time by 45% and improved next-day memory recall by 35%.

Also good for: Audio production calibration. Pink noise is used as a reference signal for equalizing speakers and room acoustics because it matches how humans perceive frequency balance.

Brown noise: emphasizes the lowest frequencies

Brown noise (also called Brownian noise or red noise) loses about 6 dB per octave. Low frequencies are much louder relative to high frequencies. The name comes from Robert Brown (Brownian motion), not the color.

To human ears, brown noise sounds deep and rumbly — like a strong river, heavy rain on a roof, or the inside of an airplane cabin. It has almost no high-frequency content, which makes it the least harsh of the three.

Technical specs:

Frequency distribution: 1/f² (loses 6 dB per octave)
Sounds like: Rushing river, heavy rain, airplane cabin
Perceived character: Deep, rumbly, soothing

Best for: Tinnitus masking and deep relaxation. Because brown noise emphasizes low frequencies, it can cover the ringing frequencies associated with tinnitus (typically 4,000–8,000 Hz) while remaining comfortable for extended listening. Many tinnitus sufferers report that brown noise is the most effective at reducing their perception of ringing.

Also popular for: The "ADHD focus" trend on TikTok, where users report that brown noise helps them concentrate. While there is no published research specifically on brown noise and ADHD, the lack of high-frequency content may reduce sensory distraction.

Side-by-side comparison

| Property | White Noise | Pink Noise | Brown Noise | |---|---|---|---| | Energy distribution | Flat (per Hz) | 1/f (per octave) | 1/f² (per 2 octaves) | | Bass emphasis | None | Moderate | Heavy | | Sounds like | Radio static | Steady rain | Rushing river | | Harshness | High | Moderate | Low | | Best use | Masking speech | Sleep, focus | Tinnitus, relaxation | | Research support | Moderate | Strong | Limited | | Natural occurrence | Rare | Common | Very common |

What about other noise colors?

The noise color spectrum extends beyond white, pink, and brown:

Blue noise (anti-pink): Emphasizes high frequencies. Sounds like a hiss. Used in dithering for audio production.
Violet noise (purple noise): Even more high-frequency emphasis than blue noise. Used in some tinnitus therapies.
Grey noise: Adjusted to sound equally loud at all frequencies to human ears (accounts for the equal-loudness contour). Sounds like a smooth hiss.

None of these have significant sleep or focus research behind them. White, pink, and brown are the practical choices.

Which one should you use?

For sleep: Start with pink noise. It has the strongest research support and works well for most people. If pink noise feels too bright, try brown noise.

For focus/concentration: Brown noise or pink noise. Both lack the harsh high frequencies that can be distracting. Brown noise is trending for ADHD focus, though research is still limited.

For masking speech: White noise. It covers the vocal frequency range most effectively. A fan or air conditioner produces something close to white noise.

For tinnitus: Brown noise or pink noise. Avoid white noise — the high frequencies can make tinnitus worse. Start at low volume and increase gradually.

For audio calibration: Pink noise. It matches human hearing perception, making it the standard reference for speaker and room equalization.

Generate and compare all three with ToneTool

ToneTool can produce all three noise types so you can compare them side by side:

Use the sine wave generator to create pure tones at specific frequencies for testing.
Use the frequency sweep to hear how frequency balance changes from low to high.
For white noise, play a sweep that covers 20–20,000 Hz rapidly.
For pink noise, sweep 20–5,000 Hz (the energy concentration range).
For brown noise, sweep 20–500 Hz (the dominant low-frequency range).

The best way to find your preferred noise type is to listen to all three at the same volume and pick the one that feels most comfortable.

FAQ

What is the difference between brown noise and pink noise?

Brown noise drops 6 dB per octave, while pink noise drops 3 dB per octave. Brown noise is deeper and more bass-heavy — it sounds like a rushing river. Pink noise sounds more balanced, like steady rain. Brown noise is better for relaxation, pink noise is better for sleep.

Which is better for sleep, brown noise or pink noise?

Pink noise has stronger research support for improving sleep. A 2017 study showed it increased deep sleep time by 45%. However, many people prefer brown noise because it sounds less harsh. Try both and see which one works for you.

What does brown noise sound like?

Brown noise sounds like a deep, steady rumble — similar to heavy rain on a roof, a rushing river, or the low hum inside an airplane cabin. It has very little high-frequency content, which makes it sound warm and smooth.

Is white noise actually white?

Yes, in the signal processing sense. White noise has equal energy at every frequency, just as white light has equal energy at every visible wavelength. However, to human ears, white noise sounds hissy rather than neutral, because our hearing is more sensitive to high frequencies.

Can noise help with ADHD focus?

Anecdotally, many people with ADHD report that brown noise improves their concentration. There is currently no published research specifically on brown noise and ADHD, but the lack of high-frequency content may reduce sensory distraction. Pink noise also shows promise for cognitive performance in laboratory studies.