We got through a ton of audio, much more then I thought we could, thanks to the help of Decoder Ring creator Gregg Taylor who manned the recording equipment. A heroic effort given he'd recently thrown his back.
There is now so much audio that it will be impossible for us to get it all in before I leave for the Game Developers Conference. However we easily have our vocal needs covered for the rest of the prototyping period, including stuff like interactive tutorials if we have time (a bit of an extravagance for a prototype, but good for testing with people new to the game).
I have a bunch of thoughts on the recording and writing process for the prototype but I'm going to keep this short and save that for another post.
Note: Wordpress seems to have added some crackle and pop to the playback, rest assured the originals are nice and clean.