Most white noise websites stream an audio file. Ours ships none. The
mixer generates every sound in your browser from raw random numbers,
then shapes that noise with audio filters until it reads as rain or
surf. Knowing how that works changes how you use the tool, because it
tells you exactly what you are hearing and what you are not.
Eight sounds from three noise colors
The engine generates three colors of noise.
White noise draws every audio sample as a uniform random value between
minus one and one. Each frequency carries similar energy, which your ear
reports as bright hiss.
Brown noise integrates randomness instead. Each sample nudges the
previous one by a small random step, the result is clamped and scaled,
and the accumulated drift piles energy into the bass. It reads as a low
rumble.
Pink noise runs a six pole filter with fixed coefficients over white
noise. Energy falls off toward the high frequencies, and the result sits
between the other two in brightness.
The eight channels map onto those three sources. Rain and the plain
white channel use white noise. Wind, cafe, and forest use pink noise.
Fire, ocean, and thunder use brown noise.
Filters turn noise into weather
Raw noise of any color is static. Each channel therefore passes through
one biquad filter before it reaches your ears.
- Rain: white noise through a bandpass centered at 1200 Hz
- Wind: pink noise through a lowpass at 350 Hz
- Fire: brown noise through a bandpass at 250 Hz
- Ocean: brown noise through a lowpass at 380 Hz
- Cafe: pink noise through a bandpass at 1600 Hz
- Forest: pink noise through a highpass at 2200 Hz
- Thunder: brown noise through a lowpass at 180 Hz
Each channel also gets an optional slow oscillator that moves its
volume. The ocean swells at 0.08 Hz, which is one swell every 12 and a
half seconds. Thunder moves at 0.06 Hz. Fire flickers faster, at 2.5
Hz. This slow movement is the difference between noise that sounds
alive and noise that sounds like a pipe. A recording of surf is loud and
quiet in a rhythm. The mixer reproduces that rhythm with one oscillator
turning a gain knob.
The generated buffer lasts four seconds at your device sample rate and
loops. Nothing downloads after page load, and no audio leaves your
machine.
The four presets by the numbers
The presets are fixed mixes you can inspect and adjust.
- Sleep: rain at 0.7, ocean at 0.5, white at 0.3
- Focus: white at 0.5, cafe at 0.4, wind at 0.2
- Relax: ocean at 0.6, rain at 0.3, forest at 0.4
- Storm: thunder at 0.5, rain at 0.7, wind at 0.5
Master volume defaults to 80 percent. When you drag a slider the change
glides in over 0.05 seconds instead of snapping, which prevents the
clicks that otherwise accompany instant gain jumps.
Set up a session in six steps
1. Open the mixer and click the preset that matches your goal, sleep,
focus, relax, or storm.
2. Listen for one full minute before changing anything. The mixes are
built to work as delivered.
3. Adjust one channel at a time. The sliders move in steps of 0.02, so
small nudges are meaningful.
4. Set the master last. Channel sliders set the balance, master sets the
overall loudness.
5. For sleep, keep the level low enough that you can still understand
someone speaking to you from a meter away.
6. Stop playback when you no longer need it. The tool keeps playing
until you press stop.
What this white noise tool does not do
Honest limits matter here because white noise carries real wellness
marketing.
The cafe channel contains no voices and no cups. It is pink noise
bandpassed around speech frequencies, and your brain fills in the rest.
Some people find that helpful. Others notice the absence of actual
speech after a few minutes.
There is no sleep timer and no fade out. Playback continues until you
stop it, which matters if you leave it running overnight.
The research picture on noise for sleep is genuinely mixed. Studies
exist on both sides, long term effects are understudied, and reviewers
disagree. Treat this as an experiment with one subject, you, and judge
it on your own mornings rather than on any blanket claim.
Background playback depends on your browser and operating system. Some
mobile systems suspend audio from a background tab, so a phone used
overnight may go silent regardless of what the tool intends.
Sustained listening at high volume costs you hearing. Keep the master
moderate, especially with in-ear headphones.
Checklist for your first week with noise
1. Start from a preset, not from eight sliders at once.
2. Change at most one channel per day so you can attribute the effect.
3. Rate your morning focus or rest on a simple one to five scale.
4. Compare a week with noise against a week without, same wake time
both weeks.
5. Drop the experiment if three nights in a row feel worse. Noise
masking is not universal.
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Did steady noise help or hurt your sleep or focus once you tracked it
for a week? That comparison is worth more than any theory about it. The
mixer described here, with all eight generated channels, runs at
https://webrecast.com/en/white-noise
