如何向我的Javascript Text to Speech添加暂停和停止功能

if ('speechSynthesis' in window) {
  // 浏览器支持Web Speech API
} else {
  // 浏览器不支持Web Speech API
}

var utterance = new SpeechSynthesisUtterance('要朗读的文本');

speechSynthesis.speak(utterance);

speechSynthesis.pause();

speechSynthesis.resume();

speechSynthesis.cancel();

if ('speechSynthesis' in window) {
  var utterance = new SpeechSynthesisUtterance('要朗读的文本');

  function speak() {
    speechSynthesis.speak(utterance);
  }

  function pause() {
    speechSynthesis.pause();
  }

  function resume() {
    speechSynthesis.resume();
  }

  function stop() {
    speechSynthesis.cancel();
  }
} else {
  console.log('浏览器不支持Web Speech API');
}