Comments on VoiceXML 2.1 draft specification

Firstly I would like to say that these small changes address some very useful additions to VoiceXML.

I am slightly disappointed that the support for <mark> does not go further and support
client side audio control. application.lastresult$.marktime will support very simple audio control
by sending the marktime as a url parameter in an audio request and having the application server
apply offsets to the original audio file. However, there are two important cases where this will not work:
- TTS prompts
- where several audio files have been queued together  (putting a mark on every prompt in the queue and
  restarting the prompt queue from the last mark would be very awkward solution)
I believe that several voice browsers already support greater functionality via non-standard extensions
and it seems a pity that these could not be standardised in VoiceXML 2.1.

I also think Teemu Tingander raises a good question about the naming of the expr attributes
for <script> and <grammar>. (Logically the expr attributes on <audio>, <next> and <submit>
should also be srcexpr. <subdialog> already uses srcexpr, but expr in this case is an asignment 
of the subdialog variable, not a definition of the subdialog fetch.) Even if there is no immediate
intention to support dynamic grammars via <grammar expr="..."/> where expr
evaluates to an actual grammar, it seems a mistake to close off that possibility in future.

Robert

Received on Tuesday, 20 April 2004 12:03:26 UTC