White Noise

Listen & Download

What Is This Sound?

This is pure white noise — the most fundamental noise signal in audio engineering. Every frequency from the lowest bass to the highest treble is present simultaneously, each carrying the same amount of energy. The result is a broad, steady “shhhh” that has become one of the most widely used sounds for sleep, focus, and audio testing.

White noise gets its name by analogy with white light, which contains all visible wavelengths at equal intensity. In the audio domain, white noise contains all audible frequencies at equal power per hertz, making it the perfect reference signal and one of the most effective masking sounds available.

How Is White Noise Created with Code?

Generating white noise with Tone.js is as simple as audio synthesis gets. The library provides a built-in Noise class that handles the random sample generation internally.

The Complete Signal Chain

import * as Tone from "tone";

// Create a white noise source
const noise = new Tone.Noise("white");

// Control the output level
const gain = new Tone.Gain(0.15);

// Connect the signal chain: Noise → Gain → Output
noise.connect(gain);
gain.toDestination();

// Start the noise
noise.start();

That is the entire implementation. The Tone.Noise("white") constructor creates a noise generator that outputs random values uniformly distributed between -1 and 1 for every audio sample. The gain node at 0.15 reduces the output to a comfortable listening level — white noise at full amplitude is quite harsh.

Under the Hood

Behind the Tone.js abstraction, the white noise generator fills an audio buffer with Math.random() * 2 - 1 for each sample. At a 44.1kHz sample rate, that means 44,100 independent random values per second, producing a statistically flat frequency distribution.

The Science Behind White Noise

Equal Energy, Flat Spectrum

White noise is defined by its flat power spectral density (PSD) — every frequency band contains the same amount of power per hertz. If you run a white noise signal through a spectrum analyzer, the plot is a flat horizontal line across all frequencies.

Mathematically, the power spectral density is constant: S(f) = N₀ for all frequencies f, where N₀ is a constant. This property makes white noise indispensable in audio engineering, acoustics research, and signal processing.

Why It Sounds “Bright”

Despite having equal energy per hertz, white noise sounds brighter or hissier than you might expect. This is because each successive octave contains twice as many hertz as the one below it. The octave from 10kHz to 20kHz contains 10,000 individual frequencies, while the octave from 100Hz to 200Hz contains only 100. Since white noise has equal energy per hertz, higher octaves carry proportionally more total energy — which is why it sounds tilted toward the treble.

Masking Effect

White noise is effective at masking other sounds because it covers the entire audible spectrum. When your brain receives a dense wall of random frequencies, it becomes harder to pick out individual sounds from the environment. This is the principle behind white noise machines used in offices, bedrooms, and therapy settings.

Common Uses

• Sleep Aid — White noise masks environmental disturbances like traffic, neighbors, or household sounds, helping maintain uninterrupted sleep
• Focus & Concentration — Creates a consistent auditory backdrop that reduces the salience of distracting sounds during work or study
• Tinnitus Relief — Audiologists frequently recommend white noise to help manage tinnitus symptoms by partially masking the perceived ringing
• Audio Testing — Engineers use white noise as a reference signal to test speakers, microphones, room acoustics, and frequency response
• Sound Design — Serves as the raw material for creating wind, rain, ocean, and other ambient textures through filtering
• Baby Sleep — Mimics the broadband sound environment of the womb, helping infants settle

Technical Details

Frequently Asked Questions

Can I use this white noise in my project?

Yes. The sound is generated by code running in your browser. The downloaded WAV file is yours to use in any personal or commercial project without attribution.

Why does white noise sound hissy compared to pink or brown noise?

White noise has equal energy per hertz, but higher octaves contain exponentially more hertz. This means the total energy increases with frequency when measured per octave, giving white noise its characteristic bright, hissy quality. Pink noise corrects for this by reducing energy at higher frequencies.

How do I loop white noise seamlessly?

Because white noise is purely random, any two segments will join together without an audible seam. Simply set your audio player or game engine to loop the file — no crossfading required.

Is synthesized white noise identical to recorded white noise?

Functionally, yes. A properly implemented digital white noise generator produces a signal that is statistically indistinguishable from recorded analog white noise. The randomness is slightly different (pseudorandom vs. true random), but for all practical audio purposes the result is the same.