@audio/auditory-octave

IEC 61260 fractional-octave filter bank

npm install @audio/auditory-octave

import octaveBank from '@audio/auditory-octave'

Standard ISO 266 center frequencies, fc = 1000 * G^(k/fraction) with G = 10^(3/10) (IEC 61260-1:2014, "Electroacoustics — Octave-band and fractional-octave-band filters"), constant-Q bandpass biquads at each fc with Q = 1/(G^(1/2n) - G^(-1/2n)).

Design function, not a stream processor: octaveBank(fraction, fs, opts) → bands. Positional fraction, then fs — a deliberate divergence from the filter/eq family's fn(data, params) in-place convention. No buffer in, no buffer out; it returns band descriptors. Feed each band's coefs to digital-filter's filter() to actually filter audio through it.

octaveBank()                                      // 1/3-octave, defaults (fraction=3, fs=44100)
octaveBank(1, 48000)                               // full-octave bank at 48kHz
octaveBank(3, 44100, { fmin: 100, fmax: 8000 })     // restrict range

| Param | Default | | |---|---|---| | fraction | 3 | Octave fraction — 1 full octave, 3 = 1/3-octave, 6 = 1/6-octave, etc. | | fs | 44100 | Sample rate Hz | | opts.fmin | 31.25 | Lowest band center Hz | | opts.fmax | 16000 | Highest band center Hz |

Use when: fixed constant-percentage-bandwidth analysis at standard ISO center frequencies — RTA/spectrum analyzers, room-acoustics measurement.

Part of @audio/auditory — the auditory family umbrella.

MIT © audiojs