Pink noise for sleep and sound testing
Pink noise is a hiss with equal energy in every octave: there's as much sound between 100 and 200 Hz as between 1,000 and 2,000 Hz. To the ear this sounds balanced, softer than white noise, like steady rain or a nearby waterfall. This page opens with it already selected; tap the round button to start.
How to use it
- Tap the round button; pink noise is already selected.
- For sleeping or studying, raise the volume gradually until it covers outside noise and pick a time under Turn off after.
- For a sound check, start with the device and mixer volume at minimum and bring it up to conversation level.
- Compare it with white and brown using the buttons next to it: the only difference between them is how much bass and treble each one has.
Help and explanations
Because it's balanced, pink noise serves two very different purposes: a background for sleeping and studying, and a test signal for live sound, because on an octave-band spectrum analyzer it shows up as a flat line.
Pink noise for tuning and testing a sound system
In PA, home theater and studio work, pink noise is the standard signal for EQ. Since its energy is equal per octave, a third-octave analyzer (RTA) shows a flat line when the speaker and the room are neutral: where the curve rises there's a resonance, where it dips sound is missing. Play the noise through the speaker, measure at the listening position and correct with the equalizer.
The noise is different on each side (decorrelated stereo), as in test generators; to measure one speaker at a time, turn the other down. To see the spectrum on your phone, use the spectrogram; to estimate the level, a sound level meter app. A phone mic isn't calibrated: it's good for before-and-after comparisons, not for certified measurements.
Pink noise and sleep
A few small studies, with a few dozen people, played pink noise in pulses synchronized with deep-sleep brain waves and saw an effect on next-day memory. That's a lab method, very different from leaving pink noise on all night, and it hasn't become a recommendation yet. In practice, pink noise is a good background for sleep because it's soft and continuous; the rest is video hype.
Tips
- On a phone speaker, pink noise still has body, while brown almost disappears. If all you have is your phone, stick with pink.
- Never start loud for a sound check: loud continuous noise heats the tweeter and tires your ears within minutes.
- For sleeping, add rain with a low mix: pink holds the background and the drops add texture.
- If pink still sounds too bright, switch to brown noise.
Frequently asked questions
What is pink noise used for?
Two things: a background for sleeping, relaxing or studying, because it's softer than white noise; and sound testing, because it has equal energy in every octave, which makes it easier to EQ speakers and rooms.
What's the difference between pink noise and white noise?
White noise has equal energy at every frequency; since the high octaves are wider, they get more energy and it sounds hissy. Pink loses 3 dB per octave and ends up with equal energy in each octave: it sounds deeper and softer.
Does pink noise help you sleep better?
Many people sleep better with a steady background, and pink is one of the most comfortable. The studies that found an effect on deep sleep used pulses synchronized with the brain, in a lab; continuous noise isn't the same thing. It's not a treatment for insomnia.
How do I use pink noise to EQ a sound system?
Play pink noise through the speaker at conversation level, measure with a third-octave analyzer at the listening position and adjust the equalizer until the curve is as flat as possible. Measure one speaker at a time and finish by checking by ear with music.
Can I download the pink noise?
There's no download: the noise is generated live, with no file, and never repeats. For a sound check, play it straight from this page with your phone or computer connected to the mixer by a 3.5 mm cable.
Can I use pink noise to help a baby sleep?
Yes, like any background sound: always quiet, with the device about 2 meters (7 feet) from the crib and never inside it. Use the timer so it doesn't play all night.