White Noise

An ambient noise machine for OVOS - "play white noise" for sleep or focus. White, pink, and brown noise, all generated, not recorded.

Usage

"play white noise"
"play pink noise"
"start some background noise"
"stop the noise"
"spil hvid støj"          (Danish)
"stop støjen"             (Danish)

Why no rain/ocean/fan sounds

The original brief mentioned rain and ocean waves too. Those need genuinely loopable recordings - a hard seam or click at the loop point would be very noticeable in a sustained ambient track, a stricter sourcing requirement than the short one-shot clips ovos-skill-sound-like uses. White/pink/brown noise sidesteps the problem entirely: noise has no coherent waveform pattern for the ear to lock onto, so a generated clip looping back to its own start is inherently seamless. Rain/ocean are a real future possibility, but need actual recordings sourced and vetted for clean looping - not built here.

How the noise is generated

• White: uniform random samples (flat spectrum).
• Pink: Paul Kellet's economy IIR filter approximation (1/f spectrum) - a well-known, publicly documented DSP technique, not sourced from any particular library or artist.
• Brown/red: a clamped random walk (1/f² spectrum).

All three use a fixed random seed, so regenerating a given noise type produces byte-identical audio - deterministic, same as every other generated sound in this project family (clicks, tones, drum hits), even though the underlying content is "random".

Why "stop" doesn't stop instantly

Same underlying reason as ovos-skill-tuning-fork: play_audio() has no reliable way to interrupt an already-playing sound. Noise loops by repeatedly re-triggering a 20-second generated clip - "stop" prevents the next clip from starting, but the clip already playing rings out to its natural end. Worst case, that's up to 20 seconds - noticeably longer than the metronome/rhythm-box's "before the next beat" stop latency, and disclosed rather than glossed over.

Install

pip install ovos-skill-white-noise

Development

See DEVELOPMENT.md.

Category

Utility

Tags

#ambient #sleep #focus #white-noise #relaxation