What are white, pink and brown noise?
All three are random sound spread across the whole hearing range. The difference is how the energy is spread out.
White noise has a flat spectrum — every frequency gets the same amount of energy. Because we hear high frequencies more easily, it comes across as bright and hissy, like static on an old TV.
Pink noise drops in strength as the pitch goes up, in inverse proportion to frequency. That balance is closer to how we actually hear, so most people find it more natural. It sounds like steady rain.
Brown noise falls away faster still — inversely to the square of the frequency. The result is deep and rumbling, closer to a waterfall or surf heard from a distance.
Blue and violet noise tilt the other way: blue gains 3 dB per octave as pitch rises, violet gains 6 dB. Both sound thin and hissy next to the others, and both put their energy where the ear is most sensitive — which is why violet noise in particular gets used for masking high-pitched tinnitus.
Lined up by slope, the set runs brown, pink, white, blue, violet: from -6 dB per octave through flat to +6. Pick by ear rather than by name — the one you stop noticing is the right one.
What people use noise for
- Sleeping through noise. A steady sound covers up traffic, footsteps upstairs, or a partner who snores.
- Focus in a shared room. Constant noise makes nearby conversation much harder to follow, so it stops pulling your attention.
- Masking tinnitus. Many people find a quiet background sound makes ringing less noticeable. Keep the volume low.
- Settling a baby. Low, even sound is often used in nurseries. Put the speaker well away from the cot and keep it quiet.
- Testing speakers and rooms. Pink noise is the usual reference for checking whether a system sounds even across the range.
- Breaking in new gear. Some listeners play noise through new speakers or headphones for a few hours. Whether it makes an audible difference is still argued over.
Which colour should you pick?
If you've never tried this before, start with pink. It masks other sounds well without the sharp hiss of white noise, and most people can leave it on for hours.
Go for brown if you're sensitive to high frequencies or you want something that feels heavier and further away. Go for white if you need to cover a specific high-pitched noise — a fan whine, a squeaky door, a keyboard in the next room.
The filters give you more control than the colour alone. Pull the low-pass down to about 2 kHz and white noise stops being harsh. Push the high-pass up to 200 Hz and you lose the rumble that some speakers turn into a buzz.
How loud should it be?
Quieter than you think. The point is to sit just above whatever you're trying to cover, not to drown it. If you have to raise your voice over the noise, it's too loud — and running anything loud for a whole night isn't good for your hearing.
For sleep, set the level while the room is quiet, then leave it. Use the timer if you'd rather it stop by itself a while after you drift off.