What Is Pink Noise? Sound, Frequencies and Sleep Research

Updated 2026-11-01

Pink noise is a steady sound with less emphasis on high frequencies than white noise. It is often described as softer or closer to a broad rushing sound. Its acoustic profile and the claims made about sleep are two different things worth understanding.

Hear this version

Listen to the balance between the low body and the higher hiss. Descriptions such as rain or rushing water are listening comparisons, not a promise that every pink-noise track is a recording of nature.

Pink Noise

Sample · 15 seconds

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A 15-second preview of the sound in the app. No automatic repeat.

What do the frequencies mean?

Ideal pink noise has equal power per octave. An octave doubles the frequency: 250–500 Hz and 500–1,000 Hz are examples. Its power per hertz decreases as frequency rises, following a 1/f model. This describes the balance of many frequencies, not a single tone.

The acoustic description explains the noise model; the sample is Night Light’s own version, not a laboratory reference signal.

Pink noise for sleep: claims and evidence

Claim	What was actually studied	What we can conclude
Pink noise improves sleep.	In a 2026 laboratory study of 25 adults over seven nights, continuous pink noise reduced REM sleep under the tested conditions. [3]	A pleasant sound is not automatically evidence of better sleep architecture.
It can influence brain activity during sleep.	A 2026 study used carefully timed brief pink-noise bursts in 14 healthy volunteers and measured changes in slow waves and cerebrospinal-fluid waves. [4]	That specialized timing is different from playing an ordinary continuous track.
Any pink-noise app reproduces those results.	The studies used specific equipment, timing, participants and outcomes. [3] [4]	We cannot transfer those findings to Night Light or promise memory or health benefits.

Pink noise can be a texture you enjoy. Choose it for how it sounds to you, while keeping laboratory findings separate from what a continuous audio track can demonstrate.

A simple way to listen

Start with a low, comfortable volume. Listen to the texture, rather than making it loud enough to cover everything.
After the sample ends, leave a short pause. Notice whether you prefer this background sound or the quiet.
If you keep listening in the app, choose the duration that suits you and use the timer when you want it to stop.

A common question

Are pink-noise pulses the same as leaving a track playing?

No. A pulse is a short event, and some experiments time it to a measured phase of brain activity. A continuous sound and a simple playback timer do not reproduce that experimental system.

Compare white, pink, brown and green noise →

Sources and further reading

Research reviewed on October 25, 2026. Results depend on the sound, volume, setting and people studied; the cited studies did not test Night Light.