SpeechSynthesisUtterance.onpause

The onpause property of the SpeechSynthesisUtterance interface represents an event handler that will run when the utterance is paused part way through (when the pause event fires.)

This occurs when the SpeechSynthesis.pause() method is invoked.

speechSynthesisUtteranceInstance.onpause = function() { ... };

var synth = window.speechSynthesis;

var inputForm = document.querySelector('form');
var inputTxt = document.querySelector('input');
var voiceSelect = document.querySelector('select');

var voices = synth.getVoices();

  ...

inputForm.onsubmit = function(event) {
  event.preventDefault();

  var utterThis = new SpeechSynthesisUtterance(inputTxt.value);
  var selectedOption = voiceSelect.selectedOptions[0].getAttribute('data-name');
  for(i = 0; i < voices.length ; i++) {
    if(voices[i].name === selectedOption) {
      utterThis.voice = voices[i];
    }
  }

  synth.speak(utterThis);

  utterThis.onpause = function(event) {
    console.log('Speech paused after ' + event.elapsedTime + ' milliseconds.');
  }

  inputTxt.blur();
}

• Web Speech API