About the sound
Resonant noise
White noise is passed through three bandpass filters tuned to 200 Hz, 300 Hz (a perfect fifth), and 400 Hz (an octave) — the same frequency ratios as the lower harmonics of any acoustic instrument. The filtering gives the noise a formant-like quality: textured and warm rather than flat. A slow LFO sweeps the root filter's cutoff by ±15 Hz on a 20-second cycle, producing the breathing movement you hear over time.
Harmonic drone
Five sine wave oscillators run at 55 Hz (A1) and its first four harmonics — 110, 165, 220, and 275 Hz. Each has its own detune LFO at a slightly different rate (0.02–0.06 Hz), so their phase relationships are always shifting but never repeat. The slow beating between them is what creates the shimmer. Amplitude decreases with each harmonic, approximating the spectral rolloff of acoustic resonators.
Binaural beats
A 200 Hz carrier splits into left and right channels. The right channel is tuned slightly higher by the beat frequency. The brain resolves the difference between the two as a perceived pulse at that frequency. At 10 Hz (alpha range), this rhythm is associated with relaxed alertness. At 6 Hz (theta), creative or meditative states. At 2 Hz (delta), deep rest. This is a real psychoacoustic phenomenon — but it only works through stereo headphones, because the two tones have to reach each ear separately.
No audio files
All sound is generated in real time by the Web Audio API using oscillators, buffer sources, and biquad filters. Nothing is loaded or streamed. The AudioContext is created on your first tap to satisfy browser autoplay policy.