Violet noise, also called purple noise, is random sound whose power rises by 6 dB with every octave, making it the brightest of the standard noise colors and the mirror image of brown noise. Almost all of its energy is in the top few octaves of hearing. It sounds like a sharp sizzle, a hi-hat held open, or steam hissing from a narrow pipe.
This page runs a free, open-source violet noise generator in your browser. The signal is computed in real time by the Web Audio API and never loops. It is a niche color, mostly used to cover very high-pitched tinnitus, for ASMR-style textures, and for testing equipment, but it is here for completeness alongside the other four colors and the perceptual grey option.
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Violet noise has no bass and almost no midrange. What remains is a fine, crystalline hiss right at the top of the audible range, closer to a whisper of air than to any rushing-water sound. People describe it as a sizzle, as the shimmer left after a cymbal crash, or as the sound of a television tube from the next room. At low volume it can be almost soothing, in the way a quiet ventilation grille is. At higher volume it is piercing.
Because it lives so far up the spectrum, violet noise disappears entirely on small speakers that cannot reproduce it and can be inaudible to people with high-frequency hearing loss. Headphones are the most reliable way to hear it as intended. If violet noise sounds like nothing at all on your device, that is usually the playback hardware rather than the generator, and moving the slider toward blue will bring the sound into a range your speakers can produce.
Violet noise has a power spectral density proportional to f². Doubling the frequency quadruples the power, a rise of 6 dB per octave. Between 1 kHz and 16 kHz, four octaves, the power climbs by 24 dB, so the top octave dominates everything below it. This is the exact inverse of brown noise, whose power falls by 6 dB per octave.
Mathematically, violet noise is the derivative of white noise, just as brown noise is its integral. Its name comes from violet light being the highest-frequency visible color. Some sources call it purple noise; the two terms mean the same thing. The complete set of power-law relationships is described on the physics page.
The generator produces Gaussian white noise and then differentiates it: each output sample is the current input minus the previous one, x[n] = w[n] − w[n−1]. That one subtraction is enough to tilt a flat spectrum up by 6 dB per octave. Blue noise is the same idea with a gentler slope, and the color slider interpolates smoothly between them, so a value of 0 is violet, 0.5 is halfway to blue, and 1 is blue.
Like everything on the site, this runs in an audio worklet for every sample, so the sound is continuous and non-repeating. No audio file is involved. Differentiation is cheap, which is one reason violet noise is easy to synthesize but rare in recordings: a recorded hiss with this much treble would suffer badly from the lossy compression most streaming uses, whereas a generated one is always clean.
Its most practical use is tinnitus masking for people whose tinnitus is a very high tone, above roughly 8 kHz, where pink and brown noise have almost no energy to cover it. A few minutes of quiet violet noise can take the edge off such a tone in a way darker colors cannot. In audio engineering, violet-shaped dither is used in some analog-to-digital converters, and audio technicians use violet noise to check tweeters and high-frequency response.
It also appears in sound design as a bright texture layer, and some listeners use it very quietly for ASMR-style tingles. The ASMR Static preset is built for that, pairing violet noise with a uniform texture and the grey EQ so the crackle is fine-grained rather than harsh. Vinyl Crackle gates the same noise into short bursts to mimic the surface noise of a record.
Start with the volume lower than you would for any other color. The ear is most sensitive between about 2 and 5 kHz, and violet noise places a lot of energy right there and above it, so it sounds louder than its meter level. The Violet Haze preset fades in over two seconds for this reason. The grey toggle applies a perceptual EQ that pulls the top end down and makes violet noise considerably more comfortable.
If you want a sound with the sparkle of violet but more body, move the color slider up toward 0.8 or 1. As with every page here, the sleep timer, shareable URL, WAV export and installable app all apply. Keep sessions with pure violet noise short at first and let your ears tell you whether it is doing what you need; if it is not, blue or white will cover most of the same ground with far less sharpness.
Yes. Both names describe noise whose power rises 6 dB per octave, proportional to frequency squared. Violet is the more common term in signal processing literature; purple is more common in casual use. The site uses violet, but you will find both on the web and they are interchangeable.
It can be useful when the tinnitus is a very high-pitched tone that darker colors do not reach. Keep the volume just below the level of the ringing rather than above it. This is not medical advice; a persistent or one-sided ringing should be assessed by an audiologist, who may also suggest a proper sound therapy plan.
Two reasons. Almost all of its power is in the top octaves, and the ear is most sensitive in the region between about 2 and 5 kHz, so the perceived loudness is far higher than for a darker color at the same level. Turning the grey EQ on, lowering the volume, or blending toward blue all help.
Both emphasize high frequencies, but violet does so twice as steeply: 6 dB per octave versus 3 dB. Blue noise still has some midrange and sounds like a fine spray of water; violet is thinner and more piercing, closer to a sizzle. On this site's color slider blue is 1 and violet is 0, with a smooth blend between.
Few people do. It contains none of the low frequencies that most sleepers find calming and its brightness tends to be alerting. If you need to cover a very high-pitched sound overnight, try it quietly with the grey EQ on, but for general sleep use the sleep presets are a better starting point.