Pink Noise — Free Online Generator
Pink noise sits between white and brown — softer than the bright hiss of white, less rumbly than the deep tones of brown. It sounds like steady rainfall, a distant waterfall, or a quiet fan. NoiseMoon generates it procedurally in your browser. No file loop. No upsell. Works offline once installed.
noisemoon
free · offline · never repeats
Audio is analyzed on-device only and discarded immediately. Nothing is recorded, stored, or transmitted.
If silent, check iPhone mute switch (side toggle).
What is pink noise?
Pink noise is a random signal whose power decreases by 3 decibels per octave as frequency rises. That gives it equal energy per octave, which roughly matches how the human ear weights frequency — the basilar membrane responds logarithmically, not linearly. The "pink" name comes from the analogy with pink light: more red (low frequency) than white light. Acoustically, pink noise sits halfway between flat white noise (0 dB/oct) and rumbly brown noise (−6 dB/oct). Naturally occurring pink-noise spectra appear in heart-rate variability, traffic flow, and many other 1/f processes. [citation needed: standard DSP textbook reference for the spectral definition]
What pink noise does
Because pink noise's spectrum tracks the ear's natural sensitivity, it sounds balanced rather than bright or dark — which is why audio engineers use it as the standard reference signal for room calibration and loudspeaker testing. For sleep, the gentler high-end roll-off makes pink noise more comfortable than white over long sessions, and a small body of research links pink-noise stimulation during slow-wave sleep to memory and sleep-quality improvements in some adults. For focus, pink noise is often the "neutral" pick — less harsh than white, less heavy than brown. Many people who try all three end up preferring pink for daytime work and brown for sleep. [citation needed: Papalambros et al. 2017 SWS pink-noise stimulation; ASA acoustic standards]
How to use it
Start at low volume — around 50 dB SPL is the commonly recommended ceiling for sustained listening. Use the warm ↔ bright slider to taste; pink sits naturally near the middle of the slider's range. The Wind preset (selected by default on this page) is a pink-base sound with a gentle bandpass filter centered around 800 Hz, giving it the quality of moving air through an open space. For deep-sleep research-style use, lower the volume further and lean toward the warm side. For focus, dial slightly bright and adjust as fatigue sets in.
Research and evidence
Pink noise has accumulated more sleep-research interest than white or brown over the past decade. A widely cited 2017 study from Northwestern (Papalambros et al.) reported that timed acoustic stimulation with pink noise during slow-wave sleep enhanced memory consolidation in older adults [citation needed]. Subsequent studies have replicated and extended this finding with mixed effect sizes. For focus and attention, pink noise has been compared favorably to silence and to white noise in multiple lab studies, though field studies are scarcer [citation needed]. For tinnitus relief, pink noise is used as one option in sound-therapy regimens, often pitched against the patient's tinnitus frequency. None of this is medical advice — consult a clinician for clinical questions.
Frequently asked
Why is it called pink noise?
Same analogy as light: pink light has more red (low-frequency) than white light. Pink noise has more bass than white noise — about 3 dB per octave more, by definition.
Is pink noise better than white noise for sleep?
Many people find pink noise softer and more sleep-friendly than white because the human ear weights low frequencies more comfortably. Some research links pink noise to deeper slow-wave sleep, though effects are modest. [citation needed]
What's the difference between pink and brown noise?
Pink noise rolls off at −3 dB/octave; brown noise rolls off at −6 dB/octave (twice as steep). Pink sounds like steady rainfall or a distant fan; brown sounds like a low rumble or distant traffic.
Does pink noise improve memory?
A line of sleep research suggests timed pink-noise stimulation during slow-wave sleep may enhance memory consolidation in some adults. Evidence is preliminary and effect sizes are small. [citation needed]
Can I use pink noise for tinnitus?
Pink noise is sometimes used as a starting masker. For clinical tinnitus, audiologists usually recommend personalized notched or matched-spectrum stimuli. NoiseMoon offers pink as one of several options.
Does NoiseMoon work offline?
Yes. Add NoiseMoon to your home screen (PWA install) and the entire app runs offline — no streaming, no buffering. The noise is generated mathematically on your device, sample by sample.