README.md

This is a JavaScript practice with JavaScript30 by Wes Bos without any frameworks, no compilers, no boilerplate, and no libraries.

23 - Speech Synthesis

view demo here

Set up elements

const msg = new SpeechSynthesisUtterance();
let voices = [];
const voicesDropdown = document.querySelector('[name="voice"]');
const options = document.querySelectorAll('[type="range"], [name="text"]');
const speakButton = document.querySelector('#speak');
const stopButton = document.querySelector('#stop');
msg.text = document.querySelector('[name="text"]').value;

The populateVoices() function

function populateVoices() {
  voices = this.getVoices();  // get all the voices
  console.log(voices);

  // select dropdown
  voicesDropdown.innerHTML = voices
    // only want en ver. voices
    .filter(voice => voice.lang.includes('en'))
    .map(voice => `<option value="${voice.name}">${voice.name} (${voice.lang})</option>`)
    .join('');
}

• to console.log(voices) will get all the voice synthesis

voices = this.getVoices();
console.log(voices);

• for select dropdown

because we only want just english versions so we filter array with includes()

voicesDropdown.innerHTML = voices
  .filter(voice => voice.lang.includes('en'))
  .map(voice => `<option value="${voice.name}">${voice.name} (${voice.lang})</option>`)
  .join('');

The setVoice() function

set the voice equals the value of select option

function setVoice() {
  msg.voice = voices.find(voice => voice.name === this.value);
  toggle();
}

The toggle() function

change voice while talking, and don't forget to call this function in setVoice() and setOption()

function toggle(startOver = true) {
  speechSynthesis.cancel();
  if (startOver) {
    speechSynthesis.speak(msg);
  }
}

The setOption() function

change the value of Rate, Pitch options and textarea

function setOption() {
  console.log(this.name, this.value);
  msg[this.name] = this.value;
  toggle();
}

Hook up events

speechSynthesis.addEventListener('voiceschanged', populateVoices);
voicesDropdown.addEventListener('change', setVoice);
options.forEach(option => option.addEventListener('change', setOption));
speakButton.addEventListener('click', toggle);
stopButton.addEventListener('click', () => toggle(false));