Phonia is an open-source toolkit for phonetic research, built for the work phonetics labs do in Praat every day: viewing spectrograms, measuring pitch, formants, and voice quality, annotating recordings, and drawing figures for publication. It runs in the browser with nothing to install, and as a desktop app for native playback and PDF export.
- Try it: https://phonia.app
- About: https://about.phonia.app
- Desktop downloads: https://github.com/mkpoli/phonia/releases
- Spectrogram — Gaussian-window STFT power spectral density in dB, wideband through narrowband, computed in viewport-independent tiles; perceptual colormaps with a grayscale ramp for print.
- Pitch — window-corrected autocorrelation candidates with a Viterbi path finder (Boersma 1993), with the full parameter surface and Praat-documented defaults.
- Formants — pre-emphasis, Burg recursion, and polynomial roots resolved to frequency and bandwidth, tracked with Xia–Espy–Wilson dynamic programming.
- Intensity — squared signal convolved with a Gaussian window, read in dB SPL.
- Voice report — glottal pulse extraction, jitter and shimmer families, HNR, CPP/CPPS, and spectral moments over a selection.
- Interval and point tiers with typed parent/child relations, an IPA input pad, and label search across the corpus.
- Praat TextGrid import and export: the reader takes the long and short text formats (UTF-8, UTF-16, or Latin-1) and the binary format.
- A recordings table with waveform thumbnails, duration and sample-rate readouts, and tagging; project files autosave and recover after a crash.
- Figures export through an SVG scene graph — the on-screen preview and the saved SVG are byte-identical. PNG export runs in the browser, PDF in the desktop app.
- Every action sits in the command palette (
Ctrl-K,⌘Kon macOS), and one undo stack covers tier edits, imports, and boundary moves.
A Rust analysis core drives two interfaces, a browser app and a Tauri desktop
app. The core is a Cargo workspace of small library crates with no UI
dependencies, compiled natively for the desktop and to WebAssembly for the
browser. Library crates carry the phonia- prefix. Each crate owns one concern:
| Crate | Responsibility |
|---|---|
phonia-audio |
Planar f32 audio with sample rate; WAV, AIFF, FLAC, MP3; resampling |
phonia-dsp |
Windows, real FFT wrappers, absolute-time frame grids, interpolation, pre-emphasis |
phonia-spectrogram |
Gaussian-window STFT spectral density in dB, viewport-independent tiles |
phonia-pitch |
Autocorrelation candidates and Viterbi tracking |
phonia-formant |
Burg analysis and formant tracking |
phonia-intensity |
Gaussian-smoothed intensity in dB SPL |
phonia-voice |
Pulses, jitter, shimmer, HNR, CPP, spectral moments |
phonia-annot |
Interval and point tiers, tier relations, invertible edits |
phonia-textgrid |
Praat TextGrid reader and writer |
phonia-project |
Versioned project files, media references, parameter profiles, autosave |
phonia-render |
Perceptual colormaps, theme-aware tile rendering |
phonia-figure |
Figure model and exporters over an SVG scene graph |
phonia-playback |
Native audio output behind a playback trait |
phonia-engine |
The API both frontends consume: commands, journaled undo, analysis cache |
phonia-wasm |
WebAssembly bindings over the engine |
Three app packages sit on the core: apps/web (SvelteKit frontend compiled to
WebAssembly), apps/desktop (Tauri shell with native playback), and apps/ui
(the Svelte component library shared by both).
Requires Rust 1.88 or newer, wasm-pack, and Bun.
bun install
bun run --cwd apps/web devThe dev task compiles the core to WebAssembly first, then serves the web app.
A production build of the web app is bun run build from the repository root;
the desktop app runs with bun run --cwd apps/desktop tauri dev.
Tests: cargo test for the core, bun run test:e2e for the end-to-end suite.
Dual-licensed under MIT or Apache-2.0, at your option.