Noise Machine

How Noise Colors Work

Noise colors are classified by their spectral density — how energy is distributed across frequencies. White noise contains equal power at every frequency, sounding like radio static. Pink noise (also called 1/f noise) decreases by 3 dB per octave, weighting lower frequencies more heavily and resembling steady rainfall. Brown noise (named after Robert Brown's Brownian motion, not the color) decreases by 6 dB per octave, producing a deep rumble like a waterfall or distant thunder. Blue noise increases by 3 dB per octave, emphasizing higher frequencies. Violet noise increases by 6 dB per octave and is the result of differentiating white noise. This tool generates each noise color algorithmically and lets you mix them independently to create your ideal ambient soundscape.

Sources

• Wikipedia — Colors of Noise
• Wikipedia — Brownian Noise
• W3C — Web Audio API Specification

Understanding Your Results

The noise machine generates continuous random audio signals with different frequency distributions, each creating a distinct sound character and serving different purposes. Noise Types: • White noise: Equal energy at all frequencies. Sounds like static or a rushing waterfall. The most commonly used type for masking environmental sounds because it covers the entire audible spectrum evenly. • Pink noise: Energy decreases by 3 dB per octave as frequency increases. Sounds deeper and more balanced than white noise — like steady rain or wind through trees. Often preferred for sleep because it more closely matches how the human ear perceives loudness across frequencies. • Brown (Brownian) noise: Energy decreases by 6 dB per octave. Sounds like deep rumbling — thunder, a strong waterfall, or a jet engine at altitude. The strong low-frequency emphasis makes it effective for masking low-pitched disturbances like traffic or HVAC noise. How Sound Masking Works: Noise masks other sounds by 'filling in' the audible spectrum so that sudden changes (like a door slamming or a dog barking) are less prominent against the background. The brain habituates to constant broadband noise, making it easier to ignore both the noise itself and the disturbances it masks. This is why many people find it easier to sleep or concentrate with noise than in silence with intermittent sounds. Volume: Effective masking requires the noise to be only slightly louder than the sounds you want to mask. Playing noise too loudly can cause ear fatigue and is counterproductive. The recommended listening level for sleep is 40–50 dB — about the volume of quiet conversation.

Noise Machine Tips

• Start with pink noise for sleep — it is generally rated as more pleasant than white noise for extended listening because its lower emphasis on high frequencies reduces the 'hissing' quality. If pink noise does not sufficiently mask disturbances, try brown noise, which has even more low-frequency energy. • Use white noise for concentration and focus in noisy environments. Its equal energy across all frequencies is most effective at masking the widest range of environmental sounds, from high-pitched voices to low rumbling traffic. • Keep volume at a comfortable level — just enough to mask distracting sounds. The American Academy of Pediatrics recommends keeping sound machines below 50 dB for sleep, roughly the volume of a quiet conversation. Prolonged exposure to louder levels can contribute to hearing damage. • Position speakers or headphones so the sound reaches you evenly. For sleep, place a speaker across the room rather than directly next to your head. This creates a more natural ambient fill and avoids one ear receiving significantly more volume than the other. • Noise machines are a tool for environmental sound masking, not a treatment for tinnitus, insomnia, or other medical conditions. While many people find them helpful, if you have persistent sleep difficulties or hearing issues, consult a healthcare professional.

Practical Examples

Example 1 — Office Focus Session Settings: White noise, moderate volume (~45 dB) Use case: Open office with colleagues talking, keyboard sounds, and occasional phone rings Effect: The broadband white noise fills in the audible spectrum, reducing the prominence of speech and sudden sounds. Most users report improved concentration within 5–10 minutes of starting. Example 2 — Nighttime Sleep Aid Settings: Pink noise, low volume (~40 dB), played through a bedside speaker Use case: Bedroom with intermittent street noise, neighbor sounds, or early morning bird calls Effect: The low-frequency emphasis of pink noise effectively masks traffic rumble and HVAC hum, while the reduced high-frequency energy avoids the 'hissing' quality that some people find irritating for sleep. Start at a volume where you can just hear it over the ambient noise.

Methodology

Generates noise using AudioBufferSourceNode from the Web Audio API. White noise uses uniform random samples. Pink noise uses the Voss-McCartney algorithm (6 first-order IIR filters) for a -3 dB/octave slope. Brown noise integrates white noise for a -6 dB/octave slope. Blue and violet noise are produced by differentiating white noise once and twice respectively. Each color has an independent GainNode for per-channel volume control. A master GainNode controls overall volume. Fade envelopes prevent audio clicks.