Noise Generator

Play white, pink or brown noise. The signal is generated on your device as it plays — no file is downloaded, so it can run as long as you like.

Protect your hearing. Noise contains every frequency at once, so it carries far more energy than a single tone at the same setting. Start at a low system volume and raise it slowly.

What the three colours mean

White noise has equal energy at every frequency. That sounds like it should be neutral, and on a measuring instrument it is — but human hearing does not work per hertz, it works per octave. The octave from 10 kHz to 20 kHz contains ten thousand hertz of bandwidth; the octave from 100 Hz to 200 Hz contains a hundred. White noise therefore packs ten times as much energy into the top octave as into the one four octaves below it, which is why it sounds thin and hissy, like an untuned FM radio.

Pink noise corrects for that. Its energy falls by 3 dB per octave, which works out as equal energy in every octave, and that is much closer to how the ear divides up sound. Pink noise is the one most people describe as sounding "flat" or "full" — closer to rain or a waterfall than to static. It is also the standard signal for audio measurement and for setting levels, for exactly this reason.

Brown noise falls faster still, at 6 dB per octave, so the bass dominates. It sounds like a distant waterfall, heavy surf, or the rumble inside an aircraft. On small speakers much of it will simply not be there, because most of its energy sits below what a laptop or phone can reproduce. For the "per hertz versus per octave" distinction behind these three colours, and why pink rather than white is the standard for measurement, see white, pink and brown noise: what the colours mean.

Finding rattles and buzzes

A pure tone asks hardware one question at a time, which makes it precise but slow: a cabinet resonance at 212 Hz is invisible to a 200 Hz tone. Noise asks every question at once. If a speaker grille buzzes, a port chuffs, a loose screw rattles, or a laptop chassis resonates, noise will usually excite it immediately where a tone sweep might walk straight past it.

The useful technique is to play pink noise at a moderate level and walk around the room. Rattles are directional and often come from the furniture rather than the speaker — a cupboard door, a window frame, a light fitting. Touching a surface while the noise plays will tell you at once whether it is the source: if the buzz stops when you rest a hand on it, you have found it, and the speaker is fine.

Setting levels

Noise is the usual signal for matching levels between speakers because it is steady. A tone's loudness depends heavily on where its frequency falls relative to a speaker's response and to the ear's own sensitivity curve, so two speakers can play the same tone at very different apparent volumes without either being at fault. Broadband noise averages across all of that, so if two speakers sound equally loud on pink noise, they are close to matched.

This tool shows its level in dBFS — decibels relative to digital full scale — which describes what leaves the browser, not what arrives at your ears. The sound pressure you actually experience depends on your system volume, your amplifier and your speakers, none of which this page can see. A number here is not a measurement of loudness in the room.

Using noise to mask sound

Many people use noise to cover distractions: traffic, a snoring partner, an open-plan office, or the perceived ringing of tinnitus. It works because a steady broadband sound raises the threshold at which intermittent sounds become noticeable, so the sudden ones stop pulling your attention. Pink and brown are usually preferred for long listening, as white tends to become fatiguing.

Two honest caveats. This is a signal generator, not a therapy: it makes no claim to treat tinnitus, improve sleep, or do anything medical, and if tinnitus is new, sudden or one-sided, that is a reason to see a doctor rather than a website. And masking works by adding sound, so it is easy to creep the volume up over hours. Prolonged exposure at high levels carries the same risk as any other loud sound.

If you hear nothing, or almost nothing

On laptop and phone speakers, brown noise in particular can sound faint or nearly absent. That is expected. Those drivers produce very little below roughly 150 Hz, and brown noise puts most of its energy under that. It is not a fault in the speaker or in this tool — it is the physical limit of a driver a couple of centimetres across. Switch to pink or white to confirm the speaker is working, and use headphones or a larger system if you want to judge the low end.

Not sure where the problem is? Run the full sound check: six quick questions, and one summary that points you at the right tool.