Hi Ronald,
I suspect you'll find that the TTS won't work well... when I test on
my phone (using the default TTS engine), even just reading English
text sounds quite robotic - so I doubt pronunciation for other
languages would be very good. There are other TTS engines you can
install, I've tested SVOX -
https://play.google.com/store/apps/details?id=com.svox.classic - and
it sounds so much better than the default engine - however this is a
paid app and you need to install a specific plugin for each voice
(eg. UK English, US English, German etc).
Being able to embed audio resources (similar to how we've done the
video resources) is on our to-do list, just that we've not got to
that yet - should be straightforward enough if we follow similar
approach to that which we did for the videos.
Although of course it does mean an overhead in the course production
process as you'd need to record all the audio ready for
distribution.
Cheers,
Alex