White noise

What white noise sounds like

White noise is the classic hiss: a fan on high, a radio between stations, air rushing from a vent. It has the same energy at every single pitch. Each octave up holds twice as many pitches as the one below it, so most of the sound ends up high, and white noise sounds bright and crisp.

The name comes from white light, which mixes all colors of light evenly. Pink noise got its name the same way: like light shifted toward red, it leans to the low end. Brown noise is the odd one out: it is named after Brownian motion, not the color.

White, pink, brown or green?

White noise has the most treble of the four. Pink noise turns the top end down for a softer sound, brown turns it down much more for a deep rumble, and green brings the middle pitches forward. If white noise feels harsh at night, try pink or brown at the same volume.

When people use it

Because it reaches so high, white noise is good at covering high, sharp sounds: chatter and keyboards in an open office, voices in a hallway, a dripping tap, the whine of a computer fan. It also stays clear on a small phone speaker, which plays high pitches well. Some people use it to block out the office at work; others pick a softer color for the bedroom.

Other colors