function _playEdgeTtsChunked(text, btn){
  return fetch('/api/tts',{body:JSON.stringify({text:chunk, voice:voice, rate:rate, pitch:pitch})});
}
function speakSelected(clean, btn, engine){
  if(engine==='edge'){
    _playEdgeTtsChunked(clean, btn);
  }
}
function speakAutomatically(clean, engine){
  if(engine==='edge'){
    _playEdgeTtsChunked(clean, null);
  }
}