White noise with the top turned down evenly, three decibels every octave, so that each octave carries as much as the one below it rather than twice as much. That is the balance of rain, surf, a waterfall and the hiss of a room, and the one an ear hears as even: where white noise hisses, this rushes, and it sits under a mix without its top end taking over. Like white noise it is not pitched, so a note does not move it — shape it with an envelope for a hit, or leave it running underneath. Tone takes the top off it, wide open by default. The generator is the white noise module's own eleven lines of audio processor, unchanged, because no node in the description makes a random signal; the slope is ordinary nodes after it. It is Paul Kellet's pinking filter: six one-pole filters side by side with their corners spread across the audible range, so that their sum falls at three decibels an octave to within a tenth of one from 10 Hz to 15 kHz, and a short direct path (b6) that keeps the highest octave from falling off with them. Every gain in it is Kellet's multiplied by 0.11, which lets its tallest swings reach full scale the way white noise's do; on average it is quieter, because most of pink noise is small.
What it is made of
The Web Audio nodes inside this module and how they are wired. Fork it to open the same graph in the editor, where every part can be changed.
A patch connects to it through audio output ‘Out’.
‘gen’ is a audioWorklet node, set to processorName atmosynth-noise, numberOfInputs 0, numberOfOutputs 1. It runs its author's own code (K21). Its output reaches input 0 of ‘b0’. Its output reaches input 0 of ‘b1’. Its output reaches input 0 of ‘b2’. Its output reaches input 0 of ‘b3’. Its output reaches input 0 of ‘b4’. Its output reaches input 0 of ‘b5’. Its output reaches input 0 of ‘b6’.
‘b0’ is a iirFilter node. Its output reaches input 0 of ‘tone’.
‘b1’ is a iirFilter node. Its output reaches input 0 of ‘tone’.
‘b2’ is a iirFilter node. Its output reaches input 0 of ‘tone’.
‘b3’ is a iirFilter node. Its output reaches input 0 of ‘tone’.
‘b4’ is a iirFilter node. Its output reaches input 0 of ‘tone’.
‘b5’ is a iirFilter node. Its output reaches input 0 of ‘tone’.
‘b6’ is a iirFilter node. Its output reaches input 0 of ‘tone’.
‘tone’ is a biquadFilter node, set to type lowpass. Its output reaches input 0 of ‘out’. A patch can set its frequency, through ‘Tone (Hz)’.
‘out’ is an audio output this module declares, set to output out.
‘Tone (Hz)’ is a setting a patch can turn, from 20 to 20000.
No published patch uses this module yet
When somebody publishes a patch built on it, that patch will be listed here.
ATMOSYNTH built-in module