title: SpeechSynthesis.getVoices() not listing voices in Firefox
body: <p>I am developing an application that requires me to use text to speech in the web browser. I am using the HTML5 Speech Synthesis for it. On Google Chrome the code runs fine, with all the available voices being listed using |getVoices()|, but in Firefox no voice is listed at all. I am testing my code on Firefox 56.0 (Ubuntu).</p>
  
  <p>On searching over the internet, I did come across a StackOverflow <a href="https://stackoverflow.com/questions/21513706/getting-the-list-of-voices-in-speechsynthesis-of-chrome-web-speech-api">answer</a> that suggested that the getVoices() function should be called after the |onVoiceChanged| event </p>
  
  <pre><code>    window.speechSynthesis.onvoiceschanged = function() {
      window.speechSynthesis.getVoices();
      ... 
  };
  </code></pre>
  
  <p>I am invoking the call in the above mentioned manner and it works as desired in Chrome, but not on Firefox. </p>
  
  <p>Another StackOverflow answer suggested that I enable the |media.webspeech.synth.enabled| in about:config of Firefox,  but in my Firefox the preference |media.webspeech.synth.enabled| is already set to true.</p>
  
  <p>I checked the MDN documentation <a href="https://developer.mozilla.org/en-US/docs/Web/API/SpeechSynthesis/getVoices" rel="noreferrer">https://developer.mozilla.org/en-US/docs/Web/API/SpeechSynthesis/getVoices</a> and the example on this page does not run for me in Firefox, but runs fine in Chrome. I found that <a href="http://caniuse.com/#feat=speech-synthesis" rel="noreferrer">CanIUse.com</a> lists that SpeechSynthesis as supported in Firefox 55 onwards, but it does not work for me.</p>
  
  <p>Also The <a href="http://mdn.github.io/web-speech-api/speak-easy-synthesis/" rel="noreferrer">demo</a> by Mozilla Developer Network to demonstrate the Speech Synthesis fails to work on my Firefox, but runs fine on Google Chrome. I have extensively searched online for a solution but could not find one. Can someone please point me in the right direction here.</p>