Playing audio backwards with HTMLMediaElement

I am trying to load and play an audio file in chrome successfully, but I can't play it backwards:

      audio = new Audio('http://ift.tt/1ENS9t9');
      audio.playbackRate = -1;
      audio.currentTime = audio.duration; // I have tried ommiting this line
      audio.play()

This produces no sound and only one timeupdate event firing.