SpeechSynthesisUtterance

const synth = window.speechSynthesis;

const inputForm = document.querySelector("form");
const inputTxt = document.querySelector("input");
const voiceSelect = document.querySelector("select");

let voices;

function loadVoices() {
  voices = synth.getVoices();
  for (const [i, voice] of voices.entries()) {
    const option = document.createElement("option");
    option.textContent = `${voice.name} (${voice.lang})`;
    option.value = i;
    voiceSelect.appendChild(option);
  }
}

// in Google Chrome the voices are not ready on page load
if ("onvoiceschanged" in synth) {
  synth.onvoiceschanged = loadVoices;
} else {
  loadVoices();
}

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

  const utterThis = new SpeechSynthesisUtterance(inputTxt.value);
  utterThis.voice = voices[voiceSelect.value];
  synth.speak(utterThis);
  inputTxt.blur();
};