@audio/speech-formant

Parallel formant filter bank

npm install @audio/speech-formant

import formant from '@audio/speech-formant'

Parallel resonator bank — each peak models one vocal tract resonance (formant).

Model: parallel combination of second-order resonators, each modeling one vocal tract mode Formant frequencies: determined by vocal tract shape; F1 controls vowel openness, F2 controls front/back Typical ranges: F1: 250–850 Hz, F2: 850–2500 Hz, F3: 1700–3500 Hz Implementation: uses @audio/filter-resonator internally — constant peak-gain bandpass per formant Defaults: F1=730 Hz (bw 90, gain 1), F2=1090 Hz (bw 110, gain 0.5), F3=2440 Hz (bw 170, gain 0.3) — open vowel /a/

formant(excitation, { fs: 44100 })   // vowel /a/ (default)

formant(excitation, {
  formants: [{ fc: 270, bw: 60, gain: 1 }, { fc: 2290, bw: 90, gain: 0.5 }],
  fs: 44100
})   // vowel /i/

| Param | Default | | |---|---|---| | formants | 3-formant /a/ bank | array of { fc, bw?, gain? } — bw default 50, gain default 1 per band | | fs | 44100 | sample rate, Hz |

Rebuilds the resonator bank only when a band's fc/bw/gain or fs actually changes (keyed by content, not object identity) — safe to reuse or mutate the same formants array across calls.

Use when: speech synthesis, singing synthesis, vocal effects, acoustic phonetics.

Not a substitute for: LPC synthesis, which estimates formants automatically from a speech signal.

Part of @audio/filter — the filter family umbrella. This README is generated from the umbrella docs.

MIT © audiojs