White noise with the treble turned down
Pink noise contains every audible frequency, like white noise, but its energy goes down as the pitch goes up: each octave has the same total energy, so on a per hertz scale the level drops by about 3 decibels per octave. Our ears hear octaves, not hertz, so pink noise sounds balanced and even, with less hiss than white noise. Many people compare it to steady rain on a roof or a light wind in the leaves.
The bars above show it: flat for white noise, a gentle slope for pink, a steep one for brown. The noise is made by your browser with a standard filter, not played from a recording, and it loops without a seam, so there is no click or gap to notice.
Pink noise and sleep
Pink noise is the color most often used in sleep research. Small studies have played it in short bursts timed with deep sleep waves and reported deeper slow wave sleep, and in some cases better memory the next day, especially in older adults. Those experiments used special equipment that follows brain waves, which a steady background sound does not do. A steady pink noise works mainly by masking: it fills the silence, so a car door or a snoring partner stands out less.
| Situation | Why pink noise fits |
|---|---|
| Falling asleep in a noisy street | Covers traffic peaks with a softer sound than white noise |
| Sharing a room | Blurs snoring and small noises without a harsh hiss |
| Reading or studying | A calm wall of sound that is easy to forget |
| Tinnitus in a quiet room | Some people find a soft background sound makes the ringing less noticeable |
Pink, white or brown?
| Noise | How it sounds | Energy by octave | Often used for |
|---|---|---|---|
| White noise | Bright hiss, like a TV between channels or an air vent | Rises with each octave (equal energy per hertz) | Masking voices and sharp sounds, focus, babies |
| Pink noise | Softer, like steady rain or wind in the trees | Equal energy in every octave (−3 dB per octave per hertz) | Sleep, long listening, a more natural sound |
| Brown noise | Deep rumble, like a waterfall or a plane cabin | Falls with each octave (−6 dB per octave per hertz) | Deep relaxation, traffic and low hum, focus |
If white noise feels too sharp and brown noise too heavy, pink noise is usually the one people keep. Tap the sound name in the sentence to switch to another color while it plays: the change is smooth, so you can compare them by ear. For something rounder still, try green noise or rain sounds.