Grey noise generator:
the most neutral sound you've never heard of

What is grey noise?

Grey noise is white noise that has been psychoacoustically equalized — adjusted so that every frequency sounds equally loud to the human ear, rather than containing equal energy at every frequency.

This distinction matters because human hearing is not flat. We're far more sensitive to mid-range frequencies (around 1–4 kHz, where speech lives) than to very low or very high frequencies. A flat spectrum like white noise sounds brighter and harsher than it "should" because our ears amplify those mid-range frequencies. Grey noise compensates for this by following the inverse of the equal-loudness contour — reducing mid-range energy and boosting the extremes — so the result sounds perceptually flat across the entire audible spectrum.

In practice, grey noise sounds softer and more neutral than white noise. Many people describe it as "white noise with the sharp edges taken off." It's less immediately striking but more comfortable for long listening sessions — which is exactly why audiophiles, tinnitus patients, and long-session focus workers often prefer it.

Grey noise vs white noise vs brown noise

Why equal energy and equal loudness aren't the same thing

This is the key concept that makes grey noise unique. In 1933, Harvey Fletcher and Wilden Munson published a study showing that human hearing sensitivity varies dramatically by frequency. We need much more energy at 100 Hz or 10,000 Hz to perceive those tones as equally loud as a 1,000 Hz tone at the same decibel level.

The resulting "equal-loudness contours" (later refined by ISO standard 226) describe how much sound pressure is needed at each frequency for a tone to sound equally loud. White noise, with its flat energy spectrum, violates these contours — it sounds too bright to our ears because we're more sensitive to the mid-range frequencies where white noise energy is high.

Grey noise inverts this: it applies the equal-loudness contour as a filter, boosting the frequencies we're less sensitive to and cutting the frequencies we're most sensitive to. The result is a sound that our auditory system perceives as equally intense across the entire spectrum — genuinely flat in perceptual terms, not just in physical terms.

When to use grey noise instead of white noise

Long focus sessions (2+ hours): White noise can cause subtle auditory fatigue in some people during extended sessions because of its bright, energetically flat spectrum. Grey noise's softer, more neutral character is easier to tolerate all day. If you find yourself wanting to turn off white noise after an hour, grey noise is worth trying.

Tinnitus masking: Tinnitus — ringing, buzzing, or hissing in the ears — most commonly affects the mid-to-high frequency range. Because grey noise accounts for our natural sensitivity to these frequencies, it can mask tinnitus more efficiently at lower overall volumes than white noise. Lower volume masking is preferable for hearing health.

Audiophile and sound-sensitive users: People with highly trained ears or significant musical experience often find white noise uncomfortable because they can hear its spectral "flatness" as a kind of brightness or stridency. Grey noise sounds more natural to trained ears — neutral in the way a well-calibrated monitor speaker sounds neutral.

Sleep: Grey noise is a comfortable all-night listening option because it's less fatiguing than white noise and more uniformly masking than brown noise. If white noise keeps you slightly alert or brown noise makes you drowsy too quickly, grey noise sits between them in character.

Grey noise for tinnitus

Tinnitus affects an estimated 15% of adults globally — around 750 million people — making it one of the most common hearing conditions in the world. While white noise is the most commonly prescribed sound therapy for tinnitus, grey noise has specific advantages that make it worth considering.

The primary goal of sound therapy for tinnitus is partial masking — raising the ambient noise floor close to the perceived volume of the tinnitus, so that the brain habituates to the tinnitus signal rather than treating it as novel or threatening. Full masking (making the tinnitus completely inaudible) is generally avoided because it prevents habituation.

Grey noise's perceptually flat spectrum means it provides equal masking power across all frequencies at a given perceived volume. For tinnitus sufferers whose phantom sound spans multiple frequencies — which is common — grey noise can be more efficient than white noise, which may over-mask some frequencies while under-masking others.

If you're using sound therapy for tinnitus, the general guidance from audiologists is to set the masking sound at the lowest volume that provides noticeable relief — never so loud that it completely covers the tinnitus. Noisescape's volume controls make it easy to fine-tune this precisely. For tinnitus, also consider our dedicated guide on white noise for tinnitus.

How to get grey noise from Noisescape

Noisescape doesn't yet have a dedicated grey noise preset (it's on the roadmap), but you can approximate the grey noise effect right now by combining White Noise with a small amount of Brown Noise:

• Set White Noise to about 60% — this provides the broadband coverage
• Add Brown Noise at about 25% — this adds low-frequency energy that compensates for our reduced sensitivity at those frequencies
• The resulting mix is warmer and more perceptually balanced than white noise alone — a close functional approximation of grey noise

Alternatively, use Pink Noise at 70–80%. Pink noise's -3 dB/octave rolloff is a step toward the equal-loudness equalization that grey noise applies, and many people who seek grey noise actually prefer pink noise once they hear both.

Other noise colours you should know

The "colour" naming convention for noise comes from the analogy to light — just as light has colours based on its spectrum, noise has colours based on how its energy is distributed across frequencies. White, pink, brown/red, and grey are the most commonly used, but there are others:

• Blue noise — energy increases with frequency (the opposite of pink). Very bright and hissy. Used in dithering in digital audio, rarely for listening.
• Violet noise — even steeper high-frequency emphasis than blue. Used in tinnitus therapy for high-frequency tinnitus specifically.
• Green noise — centred around 500 Hz, the midpoint of human hearing. Sometimes described as the sound of nature.
• Black noise — silence with occasional random bursts. Technically a noise colour but not a useful listening sound.

For practical use — focus, sleep, studying, babies, tinnitus — white, brown, pink, and grey cover the vast majority of what people actually need.

Try it free — no download needed

Every sound on Noisescape is synthesized live in your browser using the Web Audio API. Nothing is downloaded or streamed — it's all generated mathematically, in real time, on your device. This means zero latency, no loop seams, and infinite variation.