I've been very surprised and impressed at some of the out-of-the-box ideas people have had already. This is a very creative one.
I am not an audio engineer but what little knowledge I have tells me this is not likely to work given various realities and constraints we'd be dealing with, however it would definitely make for an interesting and educational experiment regardless of the outcome.
The board as it exists now could already accommodate a microphone input, all 5 of the RC channels are connected to analog inputs on the Teensy so we could just re-purpose one of those, at least for testing. Then you have to pick a mic (Adafruit, Sparkfun have convenient ones and there is an interesting design over on the
Teensy forums), and write a bunch of code.
I will add this to the list of things to explore, I probably won't get far with it myself but it would be a good project for someone who likes to tinker, once (if) these boards become available.
Keep up the creative thinking!