SpeechSynthesisUtterance 無法說中文

之前參考 Speech Synthesis API 製作 語音學習站
發現其中 中文的發音 在部分電腦可以正常發音，有些則不行

之後參考 SpeechSynthesisUtterance、Getting Started with the Speech Synthesis API 修正


// Chrome loads voices asynchronously.
window.speechSynthesis.onvoiceschanged = function(e) {
  var synth = window.speechSynthesis;
  voices = synth.getVoices();
  var voice_1 = document.getElementById('voice_1');
  while (voice_1.options.length) {
    voice_1.remove(0);
  }
  var voice_2 = document.getElementById('voice_2');
  while (voice_2.options.length) {
    voice_2.remove(0);
  }
  voices.forEach(function(voice, i) {
  var opt1 = document.createElement("option");
  opt1.textContent = voice.name + ' (' + voice.lang + ")";
  opt1.setAttribute('data-lang', voice.lang);
  opt1.setAttribute('data-name', voice.name);
  if (voice.lang == "en-US") {
    opt1.selected = true;
  }
  voice_1.appendChild(opt1);
});