SpeechSynthesisUtterance不会触发“标记”事件

Question

我无法触发mark实例的mark事件。

据我所知，这应该可行。我希望看到

SpeechSynthesisUtterance

相反，我得到

SpeechSynthesisUtterance

Started
Reached mark
Done

Started
Done

Answer 1

很抱歉让您知道这是一个错误，并且尚未实现SSML。

document.querySelector('#play').addEventListener('click', function speak() {
  const utterance = new SpeechSynthesisUtterance(
    `<?xml version="1.0"?>
    <speak version="1.1">Foo <mark name="bar" /> baz.</speak>`
  )
  
  const log = document.getElementById('log')

  utterance.addEventListener('start', () => {log.value = 'Started\n'})
  utterance.addEventListener('mark', () => {log.value += 'Reached mark\n'})
  utterance.addEventListener('end', () => {log.value += 'Done\n'})

  log.value = 'Waiting…'
  speechSynthesis.cancel()

  speechSynthesis.speak(utterance)
})

<textarea id="log" disabled rows="3">Waiting…</textarea>
<hr>
<button id="play">Speak</button>

您会发现chronium问题已经存在9年了，所以我怀疑它会很快得到解决。