Sound
Pink Noise
Broadband noise with equal power in each octave band. Its power per hertz decreases as frequency rises, giving lower frequencies more weight than white noise.
In more detail
Pink noise is a random signal whose power spectral density is proportional to 1/f, where f is frequency. Across a defined frequency range, each octave carries the same total power: the band from 100 to 200 Hz contains as much power as the band from 1,000 to 2,000 Hz.
White noise instead has equal power per hertz, so its wider high-frequency octave bands contain more total power. Pink noise therefore has less high-frequency emphasis. The name describes a distribution of sound energy, not a particular volume, recording or therapeutic effect.
Why it matters
For a bedroom or other home sound environment, the label identifies the signal's frequency balance. It does not tell you how loudly it plays, when it plays or how a person responds. Those are separate design and evaluation questions.
The common misunderstanding
Pink noise is not a clinical protocol. Continuous playback and sound triggered by a measured physiological signal are different interventions; evidence about one cannot automatically establish benefits for the other.
Sources
Last reviewed September 2026. Definitions are educational and not project-specific engineering or medical advice.