Okay so I have a quick look around I found this:
http://www.vnspeech.com/
You can grab it for free here
http://www.vnspeech.com/en/download
it does this:
"Synthesize Vietnamese speech with natural voices whose prosodics (duration, pause and amplitude) determined by a technique based on artificial neural networks.
...
- Provide 2 voices "NHMTTS Voice (Male)" and "NHMTTS Voice (Female)"."
and eventually leads back to
nghuuminh_TWOBOB_ADDED_THIS_TO_PREVE...M_@yahoo .com <-- So maybe talk to this person.
ALSO I found...
https://addons.mozilla.org/en-us/fir...ietnamese-tts/ <-- This one I traced like this:
https://addons.mozilla.org/en-us/fir...efaults.js#top
Which led me to:
http://hmt.no-ip.org:13009/texttospeech/
which led me to
hoanb1_TWOBOB_ADDED_THIS_TO_PREVENT_SPAM_@gmail.co m <-- So maybe talk to this person.
That was all I could find.
Hope it helps.