title: TTS software used in chrome for SpeechSynthesis
body: <p>Any idea what software does chrome use with <code>SpeechSynthesis</code> js API? I mean the built-in one powering this <a href="https://mdn.github.io/web-speech-api/speak-easy-synthesis/" rel="nofollow noreferrer">demo</a>. I would like to capture synthesized voice into .wav (or other format), in my web app, but seems very <a href="https://stackoverflow.com/a/70665493/350334">inconvenient via available javascript apis</a>. I was thinking if chromium uses open source software here, I could compile it into wasm...</p>
  <p>I found some references to <a href="https://chromium.googlesource.com/chromium/src/+/refs/tags/74.0.3729.5/docs/accessibility/espeak.md" rel="nofollow noreferrer">espeak-ng</a>, however espeak-ng output quality is much worse compared to <code>SpeechSynthesis</code> js. There is also <a href="https://chromium.googlesource.com/chromium/src/+/refs/tags/74.0.3729.5/docs/accessibility/patts.md" rel="nofollow noreferrer">PATTS</a> mentioned or <code>chrome-tts-blaze</code> but seems outdated and links broken.</p>
  <p>I also compared quality with <a href="https://github.com/festvox/flite" rel="nofollow noreferrer">flite</a> using available .flitevox voices, but quality not good either.</p>