Mozilla has yet to implement SpeechRecognition interface for Firefox, so I turn the challenge into Stephen Hawking’s voice synthesizer. Utter the words you type, darling!

It only requires 13 lines of JavaScript code (including the comments). Here’s the demo.

Markup

  <h1 class="title">Type What You Say <span>&#128266;</span></h1>

  <div class="words" contenteditable>
  </div>

  <script src="scripts.js"></script>

JavaScript