title: Chrome text-to-speech API doesn't work
body: <p>I'm trying the chrome text-to-speech API but even the demo provided by google
  <a href="https://developer.chrome.com/trunk/extensions/examples/extensions/ttsdemo/ttsdemo.html">https://developer.chrome.com/trunk/extensions/examples/extensions/ttsdemo/ttsdemo.html</a>
  doesn't work for me, I can't hear any sound, do you?</p>
  
  <p>I don't think it is a problem of my browser because google.translate.com (which I guess is based on the same technology) works for me if I try the listening mode.</p>
  
  <p>Any idea?</p>
  
  <p>Thanks</p>