Provides a description of a non-speech audio source in <audio>.

None

<?xml version="1.0"?>
<vxml version="2.0">
  <form>
    <block>
      <prompt>
        I'm going to play an audio file.
      </prompt>
      <audio src="http://nonexistent.domain.com/test.wav">
        Oops, the audio file could not be retrieved!
        <desc>
        If the wave file at the location specified by the "src" attribute can not be retrieved, 
        the text within the "audio" tag will be read by the TTS engine.
        </desc>
      </audio>
    </block>
  </form>
</vxml>

The output of the above script would be:

Computer: I'm going to play an audio file.
Computer: (plays audio file if available)

None

<audio>