Можно ли выбрать слово, которое читается при использовании API SpeechSynthesisUtterance?

Question

Можно ли выбрать слово, которое читается при использовании API SpeechSynthesisUtterance ?

Есть ли событие, которое я могу использовать, чтобы получить текущее произнесенное слово и позицию курсора?

Вот что у меня есть:

var msg = new SpeechSynthesisUtterance();
var voices = window.speechSynthesis.getVoices();
msg.voice = voices[10]; // Note: some voices don't support altering params
msg.voiceURI = 'native';
msg.volume = 1; // 0 to 1
msg.rate = 1; // 0.1 to 10
msg.pitch = 2; //0 to 2
msg.text = 'Hello World';
msg.lang = 'en-US';

msg.onend = function(e) {
  console.log('Finished in ' + event.elapsedTime + ' seconds.');
};

speechSynthesis.speak(msg);

Пример из здесь .

Answer 1

Был связанный вопрос , который выписал слова в промежуток, и я расширил этот ответ до выберите слова как они естьговорят.

var utterance = new SpeechSynthesisUtterance();
utterance.lang = 'en-UK';
utterance.rate = 1;

document.getElementById('playButton').onclick = function(){
    var text = document.getElementById('textarea').value;
    // create the utterance on play in case user called stop
    // reference https://stackoverflow.com/a/47276578/441016
    utterance = new SpeechSynthesisUtterance();
    utterance.onboundary = onboundaryHandler;
    utterance.text = text;
    speechSynthesis.speak(utterance);
};

document.getElementById('pauseButton').onclick = function(){
    if (speechSynthesis) {
      speechSynthesis.pause();
    }
};

document.getElementById('resumeButton').onclick = function(){
    if (speechSynthesis) {
      speechSynthesis.resume();
    }
};

document.getElementById('stopButton').onclick = function(){
    if (speechSynthesis) {
      speechSynthesis.cancel();
    }
};

function onboundaryHandler(event){
    var textarea = document.getElementById('textarea');
    var value = textarea.value;
    var index = event.charIndex;
    var word = getWordAt(value, index);
    var anchorPosition = getWordStart(value, index);
    var activePosition = anchorPosition + word.length;
    
    textarea.focus();
    
    if (textarea.setSelectionRange) {
       textarea.setSelectionRange(anchorPosition, activePosition);
    }
    else {
       var range = textarea.createTextRange();
       range.collapse(true);
       range.moveEnd('character', activePosition);
       range.moveStart('character', anchorPosition);
       range.select();
    }
};

// Get the word of a string given the string and index
function getWordAt(str, pos) {
    // Perform type conversions.
    str = String(str);
    pos = Number(pos) >>> 0;

    // Search for the word's beginning and end.
    var left = str.slice(0, pos + 1).search(/\S+$/),
        right = str.slice(pos).search(/\s/);

    // The last word in the string is a special case.
    if (right < 0) {
        return str.slice(left);
    }
    
    // Return the word, using the located bounds to extract it from the string.
    return str.slice(left, right + pos);
}

// Get the position of the beginning of the word
function getWordStart(str, pos) {
    str = String(str);
    pos = Number(pos) >>> 0;

    // Search for the word's beginning
    var start = str.slice(0, pos + 1).search(/\S+$/);
    return start;
}

<textarea id="textarea" style="width:100%;height:150px;">
Science Literacy is a way of approaching the world. It's a way of equipping yourself to interpret what happens in front of you. It's methods and tools that enable it to act as a kind of a utility belt necessary for what you encounter in the moment. It's methods of mathematical analysis, interpretation, some basic laws of physics so when someone says I have these two crystals and if you rub them together you get healthy. Rather than just discount it, because that's as lazy as accepting it, what you should do is inquire. 

So do you know how to inquire? Every scientist would know how to start that conversation. Where did you get these? What does it cure? How does it work? How much does it cost? Can you demonstrate? Science literacy is vaccine against charlatans of the world that would exploit your ignorance of the forces of nature. Become scientifically literate.
</textarea><br>
<input type="button" id="playButton" value="Play"/>
<input type="button" id="pauseButton" value="Pause"/>
<input type="button" id="resumeButton" value="Resume"/>
<input type="button" id="stopButton" value="Stop"/>

Синтез речи MDN
Синтез речи MDN
Граница MDN

Answer 2

var msg = new SpeechSynthesisUtterance();
var voices = window.speechSynthesis.getVoices();
msg.voice = voices[10]; // Note: some voices don't support altering params
msg.voiceURI = 'native';
msg.volume = 1; // 0 to 1
msg.rate = 1; // 0.1 to 10
msg.pitch = 2; //0 to 2
txt = "I'm fine, borderline, so bad it hurts Think fast with your money cause it can't get much worse I get told that I'm far too old for number one perks".split(" ")
msg.text = txt;
msg.lang = 'en-US';

msg.onend = function(e) {
  console.log('Finished in ' + event.elapsedTime + ' seconds.');
};

var gap = 240
var i = 0
speakTrack = setInterval(() => {
  console.log(txt[i++])
  //i++ < dont forget if you remove console log
  if (i >= txt.length) {
    i = 0
    clearInterval(speakTrack)
  }
}, gap)

speechSynthesis.speak(msg);

Как насчёт этого?

Демо