Hi,
The slide duration in presenter is automatically adjusted according to the time of the audio inserted on that slide.
How are you inserting audio on slide ? Recording or inserting using presenter option ?
You cannot create a movie format like avi, mp4 etc
But you may publish the presenttaion in the swf format which will play in a browser or a swf player. To play in the broswer you just need to have Adobe Flash Player installed on your system. It will play like a movie in the broswer.
Let me know if you need some more help
Thanks,
Alpi Agarwal
Adobe Presenter Engineering Team