White noise

Equal power at every frequency — the bright hiss that masks almost anything.

White noise Generated live in your browser

Tap a second sound to layer it — rain under brown noise, for instance.

What is white noise?

White noise is the reference point all the other colours are named against. It carries equal power at every frequency, which makes its spectrum flat and its sound bright and hissy. Because human hearing is most sensitive in the upper-middle range, that flat spectrum is heard as treble-heavy, which is why many people find white noise sharp and reach for pink or brown noise instead.

This page is a white noise generator: the sound is computed in your browser rather than streamed from a file, so it starts instantly and never reaches a loop point. More on how that works.

Good for

  • Masking irregular noise: voices, doors, traffic that comes and goes
  • Shared bedrooms, thin walls, hotel rooms
  • Anyone who wants the broadest masking rather than the gentlest sound

The details

Spectrum
Flat — equal power at every frequency
Slope
0 dB per octave
Sounds like
Untuned radio static, a strong hiss
Named after
White light, which contains every visible wavelength

Questions

Is white noise safe to use every night?

For adults there is no established harm in nightly use at a moderate volume. The common guidance is to stay below roughly 50 decibels — about the level of a quiet conversation — and to place the source across the room rather than beside your head. That advice matters more for infants, whose cots are sometimes placed very close to a machine.

Does white noise actually help you sleep?

The honest answer is that the evidence is mixed. Reviews of the research find that continuous noise can help people fall asleep faster in noisy environments, but the studies are small and inconsistent in quality, and a few suggest it may fragment sleep in some people. What is far less disputed is the masking effect: a steady background reduces the contrast between silence and a sudden sound, and it is that contrast that wakes you.

Why does white noise sound so harsh?

Because equal power per frequency is not equal loudness to your ear. Human hearing peaks in sensitivity around 2 to 5 kHz, so the flat upper half of the spectrum is perceived as much louder than the lower half. Pink and brown noise correct for that by rolling off the highs, which is why they sound softer at the same measured level.

Every colour of noise

Beyond the colours

Not noise colours in the strict sense, but built from them — and useful for the same reason.