The latest Firefox update has broken the text to speech. We are working on a fix. Internet explorer should still be working.
yo soy con Explorer mais ça ne marche pas pour moi non plus...
Thanks for letting us know about IE. We're spending some time on these issues and aim to have text-to-speech working for all browsers in our next update. For now, I notice that Chrome is working properly, so I might recommend using that in the meantime.
@nestorga - If you prefer using Firefox, you can also downgrade to version 12.0, in which text-to-speech should still be working properly.