SleepByNoise

Grey Noise

Grey noise is the connoisseur's color: instead of being flat by the numbers, it is shaped to sound flat to your ears. Press play to hear a noise engineered to feel perfectly even across the whole spectrum.

Human hearing is more sensitive to mid frequencies than to the extremes, so mathematically flat white noise actually sounds brighter than it is. Grey noise corrects for this using an equal-loudness curve, so no part of the spectrum stands out.

Grey Noise

Perceptually flat — engineered to sound even to your ears.

Volume60%
ToneBright
Waves
Timer

What is grey noise?

Grey noise is white noise passed through a psychoacoustic equal-loudness filter (based on curves like the ISO 226 standard). It boosts the frequencies our ears are less sensitive to and eases back the ones we hear most strongly, so the perceived loudness is even everywhere.

The effect is a smooth, neutral, balanced sound — arguably the most 'complete' feeling noise, without white's harsh top end or brown's heavy bottom.

Uses and benefits of grey noise

Grey noise is prized for masking and for hearing-related uses because of its perceptual balance.

  • Balanced masking: covers distractions evenly without any frequency poking through.
  • Tinnitus: used in some sound-therapy contexts for its neutral profile.
  • Focus: a refined, non-fatiguing backdrop for long work sessions.
  • Audiology: related shaped noise is used in hearing assessment.

Frequently asked questions

What is the difference between grey noise and white noise?

White noise has equal energy at every frequency by measurement, so it sounds bright to human ears. Grey noise is reshaped to an equal-loudness curve so it sounds balanced to us — no part of the spectrum feels louder than another.

Is grey noise good for sleep or focus?

Yes. Because grey noise is perceptually even, many people find it a smooth, non-fatiguing backdrop for both sleep and long focus sessions. Try it against pink and brown noise to see which you prefer.

Explore more

White noiseNoise for focusNoise for tinnitusAll colors of noise
Last updated August 23, 2026