​

​

window.onload = () => {

​

play.onclick = (e) => {

  var u = new SpeechSynthesisUtterance();

  u.text = 'Hello World. This is a large test.';

  u.lang = 'en-US';

  u.rate = 1.0;

  let boundaryIdx = 0;

  u.onboundary = function(event) {

    let word = u.text.substring(boundaryIdx, event.charIndex);

    boundaryIdx = event.charIndex;

    console.log('boundary', word, event); 

  };

  speechSynthesis.speak(u);

};

};