Noise Generator: Play White Noise, Pink Noise & Brown Noise
Overview
Noise Generator. Pick White, Pink, or Brown Noise with the Noise Generator, adjust the volume slider, and hit Play Noise to fill the room with a steady, even sound for focus, masking distractions, easier sleep, or breaking in new speakers. Set the auto-stop timer if you want it to shut off on its own. To find a hum, a whistle or a resonance peak, use the free spectrum analyzer and watch the frequency spectrum update in real time.
A dripping tap, a neighbour's TV or traffic at 2 a.m. can keep your mind busy long after you want it quiet. This noise generator is free, needs no signup and runs in your browser: press play on white, pink or brown noise or rain sounds, and you get a steady audio bed that hides sudden noise, so sleep and focus come easier.
How to Use This Free Noise Generator
This white noise generator runs entirely in the browser tab, so there is nothing to install. The free online generator starts when you click Play, because browsers block audio until you interact with the page. Hearing changes with age, and the frequency sweep test sends a rising tone so your ears can tell you where audible sound ends.
Noise Types, Presets and Custom Sound Mixes
Start by choosing one of the noise types, then shape it with the options below.
Core Colours in the Noise Generator
White, pink and brown are the core colours. If white noise generator sounds feel too synthetic, try a colour lower in pitch.
Rain and Nature Sounds in a White Noise Generator
The rain option in this generator adds a texture closer to nature sounds such as rainfall, ocean waves or distant thunder. It plays one sound at a time; for presets, mono or stereo width and custom sound mixes that layer a fan with soft pink noise, use a dedicated mixer site. A white rain noise generator uses recorded rain whose spectrum matches white noise.
Volume Slider, Sleep Timer and Visualizer
- Volume slider: changes the level in real time, so you can tune it while the disturbance is happening.
- Sleep timer: stops playback after a set time and shows a countdown, handy when you want to fall asleep without sound until morning.
- Visualizer: animated bars that give a feel for the noise colour, not a lab-grade frequency spectrum.
- Play and Stop: start or end the sound; some players also fade in gently.
Because the noise generator creates the audio on the fly, it keeps working offline once loaded, though long playback uses battery.
Pink Noise, Brown Noise and Other Noise Colors Compared
White noise, pink noise and brown noise are all random sound, but they spread their energy across the frequency spectrum differently. Human hearing covers roughly 20 Hz to 20 kHz, and each of these noise colors tilts that range a different way. That is why white sounds like a bright hiss or radio static, pink like steady rain, and brown like a deep rumble or a waterfall. Colored noise with less treble causes less listening fatigue. Speaker wiring can flip positive pressure into negative, and the absolute polarity blind test online checks whether you notice the inverted waveform.
| Noise colour | Slope (dB per octave) | Sounds like | Often chosen for |
|---|---|---|---|
| White | 0 (equal energy per Hz) | Hiss, TV static | Loud rooms, voices, tinnitus |
| Pink | -3.01 | Steady rain, wind | Study, all-round use |
| Brown | -6.02 | Rumble, waterfall | Sleep, a racing mind |
| Violet | +6.02 | Sharp, high hiss | Rarely used for sleep |
The Noise Color Formula: Level Change per Octave
Every noise color follows a power law: its power at each frequency is proportional to \(1/f^{\beta}\), where \(\beta\) is 0 for white, 1 for pink and 2 for brown. The level difference between two frequencies is:
$$\Delta L = -10 \times \beta \times \log_{10}\left(\frac{f_2}{f_1}\right)\ \text{dB}$$
Doubling the frequency gives the slope in decibels per octave: 3.01 for pink, 6.02 for brown. Take a low hum at 160 Hz and a speech sound at 2,560 Hz, four doublings higher. White noise has the same level at both. Pink is 12.04 dB quieter at 2,560 Hz, and brown 24.08 dB quieter. So brown keeps its energy in the bass, while white holds the same level at 1 kHz as everywhere else and the treble stays strong.
Brownian Noise, Red Noise and Violet Noise
Brown noise has nothing to do with colour: it is named after Brownian motion, the random jostling of particles, so it is also called Brownian noise, or red noise, after the low end of the visible spectrum. Violet noise is the opposite, rising 6.02 dB with each doubling. A brown noise generator builds that low rumble from a running sum of random numbers.
Masking a Late Tram with the Brown Noise Generator
The decision is simple: can a second-floor flat beside a tram line get through a work week of sleep without earplugs, and if so, at what volume? The answer comes out at about 39.5 dBA of brown noise, which cuts each tram's jump from 18.7 dB to 8.1 dB.
First come the numbers. A phone sound meter on the pillow reads a floor of 28.6 dBA at 23:40, and the 23:52 tram peaks at 47.3 dBA. That peak matters because the WHO's community noise guidelines suggest single events in a bedroom stay under 45 dBA; this one breaks it by 2.3 dB, and an 18.7 dB jump is exactly the kind of contrast that wakes people.
I pick brown rather than white because the tram's rumble is low, then raise the volume slider while the next tram passes and read the meter with the noise alone. Decibels add as power, not as plain numbers, so I check each step by hand with \(10 \log_{10}(10^{L_1/10} + 10^{L_2/10})\):
| Brown noise level | New floor | Tram peak | Jump |
|---|---|---|---|
| None | 28.6 dBA | 47.3 dBA | 18.7 dB |
| 37.5 dBA | 38.0 dBA | 47.7 dBA | 9.7 dB |
| 39.5 dBA | 39.8 dBA | 48.0 dBA | 8.1 dB |
| 41.5 dBA | 41.7 dBA | 48.3 dBA | 6.6 dB |
Solving for a 10 dB jump gives 37.1 dBA, so that's the floor below which the noise does little. I settle on 39.5 dBA: every extra 2 dB above it buys only about 1.5 dB less contrast while adding to all-night exposure.
The caveat a meter won't show: dBA readings weight down bass, and the upstairs neighbour's footsteps are mostly thumps under 100 Hz. On the meter they barely register, yet they still wake me, which is why brown noise beats white here even at the same dBA. My judgement is that the input to watch is the floor reading, not the peak. A fridge cycling on lifts the floor by a decibel or two and shifts every number in the table, so I'd measure on two different nights before trusting one result. If the jump stays above 10 dB at a volume you can tolerate, the noise generator alone isn't enough; that's the point to add earplugs or seal the window instead.
How a Sound Generator Makes Noise in Your Browser
A good noise generator, like any sound generator built for the web, doesn't stream an audio file. It uses the browser's Web Audio API to compute the signal on-device, sample by sample, in real time. For white noise, a random number generator fills each sample with a fresh value, giving uncorrelated samples and a flat spectral density across all audible frequencies. At a 44.1 kHz sample rate that is 44,100 new values every second.
The pink setting passes those values through a filter, often Paul Kellet's well-known design. Brown comes from a leaky-integrator: each new value adds a little randomness to the last, a leaky-integrated random walk that stays near zero instead of drifting off. Some generators add a low-pass filter to soften what remains of the high end.
Synthesized noise also avoids a weakness of pre-recorded audio. A recording played in a loop repeats: a 4-second buffer loops 900 times an hour, and the ear can learn the pattern. Live generation, or long loops crossfaded at the joins, never repeats noticeably. Repeats stand out most between roughly 2 and 4 kHz, where hearing is most sensitive.
Colored Noise for Sleep and Focus
Whatever you use an ambient sound generator for, it relies on one psychoacoustic effect, so start there.
Noise Masking and the Noise Floor
Noise masking works because your brain reacts to sudden change, not to loudness itself. A quiet room has a low noise floor, so a door slam stands far above the ambient noise. Steady sound raises that floor, and frequency masking hides the parts of a disturbance in the same range. In acoustics terms: a bedroom has background noise of 31 dBA, and a passing truck peaks at 52 dBA, a jump of 21 dB. Add 44 dBA from a white noise generator and the floor rises to 44.2 dBA while the peak becomes 52.6 dBA, so the jump shrinks to 8.4 dB. Traffic, voices, conversations, snoring and noisy neighbors work the same way: you don't need to mask a sound completely, only shrink its contrast.
A White Noise Generator for Tinnitus Relief and Babies
For tinnitus relief, steady noise from a noise generator gives your hearing something other than the ringing to attend to, a basic form of sound therapy. Parents use white noise machines because a constant hum resembles what a baby heard in the womb. With infants, keep the machine away from the crib and the level low.
Concentration, ADHD and Open Office Privacy
For concentration, a steady audio bed from the noise generator hides the half-heard speech that breaks your thought while studying. Many people with ADHD, autism or sensory sensitivity say brown noise helps them study, though research on noise colour itself is thin. In an open office, play pink or brown noise from the noise generator through headphones at a low volume to blur nearby speech, gaining acoustic privacy and keeping productivity up.
A Noise Generator for Deep Sleep, Relaxation and Meditation
Sleep specialists point to masking as the main way noise helps sleep quality: fewer sudden contrasts can mean shorter sleep onset and fewer nighttime awakenings breaking deep sleep. Brown noise suits relaxation, meditation and stress relief, and some listeners find it eases anxiety at bedtime.
How Loud to Set a White Noise Generator
The most common mistake with any white noise generator is setting it too loud. Even a free white noise generator can run all night if you treat volume as the setting that matters.
Find the Minimum Volume That Still Masks
- Set it up at night, in your room, while the disturbance (traffic, an air conditioner, a partner snoring) is present.
- Raise the noise generator's volume until the disturbance stops pulling your attention.
- Lower it until masking just starts to fail, then nudge it back up. That is your minimum volume.
A quick calibration check: if you would need to raise your voice to talk over the noise, it's louder than the job needs.
Safe Decibels for All-Night Listening
Measure in decibels if you can; a free phone sound meter is close enough. The US EPA set a 70 decibels 24-hour average to protect hearing, so all-night audio from a white noise generator at the example's 44 dBA leaves a wide margin. For a nursery, stay at or below the 50 dBA limit recommended for hospital nurseries.
Frequently Asked Questions
- What is the difference between white, pink and brown noise?
- They spread energy differently across the spectrum. White noise has equal energy at every frequency and sounds like a hiss, pink noise falls about 3 dB per octave and sounds like steady rain, and brown noise falls about 6 dB per octave for a deep rumble.
- Is this noise generator free?
- Yes. It is free to use, with no signup, no account and no time limit.
- Is the sound a recording?
- No. The noise is synthesized live in your browser with the Web Audio API, so nothing is streamed or downloaded and the sound never loops back on a short pattern.
- Why is there no sound until I press Play?
- Browsers block audio until you interact with the page. One click on Play unlocks it.
- Can I leave the noise generator on all night?
- Yes, at a moderate volume. Use the sleep timer if you want it to stop on its own; otherwise it keeps playing until you press Stop or close the tab.
- Does it keep playing if I lock my phone or close the tab?
- Closing the tab stops it, and many mobile browsers pause or throttle audio once the screen locks, so keep the screen awake or use a desktop browser for long sessions.
- How loud should I set it?
- Lower than you think. Raise the volume until the disturbing sound stops grabbing your attention, then ease it back to just above the point where it starts getting through.