Noise generator
All of the colours in one player. Switch while it plays — that is the only way to actually hear the difference between brown and pink rather than read about it.
Noise colours are named by how their energy is spread across the spectrum. White is flat — equal power at every frequency. Pink falls by 3 dB per octave, brown by 6, so each one sounds progressively deeper. Blue and violet tilt the other way, and grey is shaped to sound equally loud across the range to human ears.
The colours, and when each one is the right answer
| Colour | Slope | Sounds like | People use it for |
|---|---|---|---|
| White | Flat | Untuned radio, bright hiss | Masking speech and keyboards |
| Pink | −3 dB/oct | Steady rain, a waterfall further off | Sleep and long sessions where white is too sharp |
| Brown | −6 dB/oct | Distant thunder, a jet cabin | Traffic rumble, focus, sleeping through a noisy street |
| Green | Mid-band | Wind through trees, a river | A softer bed that does not feel like a machine |
| Grey | Loudness-shaped | Full but balanced | When white feels tinny and brown feels muddy |
| Blue | +3 dB/oct | Bright, airy hiss | Rarely used alone; mostly an audio-engineering tool |
How to choose in ten seconds
- Start the player above on brown and leave it for twenty seconds.
- Switch to pink. If the room suddenly feels clearer, the thing bothering you is in the mid range — voices, keyboards, television through a wall.
- Switch to white. If that feels harsh rather than clearer, go back to pink and stay there.
- Set the level so that the noise is quieter than the sound you are trying to cover. Masking works at surprisingly low levels; loud noise is just a different intrusion.
Does noise actually mask sound, or just distract from it?
It genuinely masks. A steady broadband sound raises the floor so that a smaller, irregular sound no longer stands out against silence — this is ordinary psychoacoustics and it does not require any claim about brain states. It works best when the noise overlaps the frequency range of whatever you are covering, which is why the colour choice matters more than the volume.
Every colour on its own page
Questions
What is the difference between white and brown noise?
White noise has equal energy at every frequency and sounds bright, like a hiss. Brown noise drops by 6 dB for every octave upward, so almost all of its energy is low — it sounds like distant thunder or an aircraft cabin.
Which noise colour is best for sleep?
Most people prefer pink or brown for sleep because the high frequencies in white noise feel harsh over hours. There is no strong evidence that one colour outperforms another; comfort is the deciding factor.
Is it safe to run noise all night?
At a low volume, yes for most people. Keep it below conversation level — sound played for eight hours at high volume is a hearing risk, and masking works quietly.
Does this use a looped recording?
No. The noise is generated in your browser from a random source and shaped by a filter, so there is no loop point to notice and nothing to download before it plays.
Running this on a phone? The Brainwave Generator app keeps playing with the screen off, works without a connection, and carries the same engine. Free on iOS and Android.