White noise basics
What is white noise?
White noise is a steady hiss that contains every audible pitch at the same strength. It is used to sleep, to concentrate and to settle babies.
White noise is a sound that has equal energy at every frequency we can hear, so it sounds like a steady "shhh", like static or a radio between stations. People use it to mask other noise, to sleep, to focus and to soothe babies.
What white noise sounds like
Think of television static, a radio tuned between stations, a running tap or air rushing from a vent. It is bright, hissy and has no tune, no rhythm and no words.
You can hear it right now in the free white noise generator.
Why it is called "white"
The name comes from white light, which is a mix of all visible colors. White noise is a mix of all audible frequencies at equal strength. Other "colors" of noise, such as pink and brown, have more energy in lower pitches. See the colors of noise.
How it works
A random signal with equal power at every frequency is white noise. Each sample is independent of the one before it, so there is no pattern. In practice, our ears are more sensitive to high pitches, so white noise sounds bright and hissy. The details are in how white noise works.
What it is used for
- Sleep. It masks sudden sounds such as traffic and doors. See white noise for sleep.
- Babies. It is the most common baby sleep sound. See white noise for babies.
- Focus and study. It covers distractions. See white noise for studying.
- Tinnitus. Sound therapy can make ringing less noticeable. See white noise for tinnitus.
- Privacy. Offices use sound masking to hide conversation.
- Engineering. It is used to test audio equipment and as a random signal in electronics.
White noise vs other sounds
| Type | Sounds like | Energy |
|---|---|---|
| White noise | Bright hiss, static | Equal at all frequencies |
| Pink noise | Steady rain, wind | More in the lows |
| Brown noise | Deep rumble, thunder, strong wind | Much more in the lows |
Compare them in white vs pink vs brown noise.
Is "white noise" a general name for all steady sounds?
In everyday speech, yes. Fans, rain, ocean and engines are often called white noise even though they are not technically flat in frequency. That is how the term is used for sleep sounds, and how this site uses it too.
Is white noise safe?
At low volume, for most people, yes. For babies, follow the volume and distance guidance in white noise safety. For adults, avoid loud levels for long periods, and talk to a doctor if you have hearing concerns.
Try it
Use the free generator in your browser, or get Baby White Noise on your phone for 20 sounds, a sleep timer and offline playback.
Frequently asked questions
What is white noise in simple words?
A steady, hissing sound like static, made of all pitches at equal strength.
Why is white noise good for sleeping?
It masks sudden noises and gives a steady sound to relax into. Research is mixed. See white noise for sleep.
What is the difference between white noise and pink noise?
White noise is brighter. Pink noise has more low pitches and sounds softer, like steady rain.
Is white noise bad for you?
Not at moderate volume. Loud sound for long periods can damage hearing.
Who invented white noise?
No one person did. The term comes from signal theory and acoustics in the 20th century. See the history of white noise.
This page is general information, not medical advice. Talk to your pediatrician about your baby's sleep and hearing, and follow current safe sleep guidance.