Generally speaking, you'll want to check out which audio system you want, PulseAudio, OSS, ALSA and then Jack for making the connections to your mics. Here's a bit of starter: http://www.penguinproducer.com/Blog/201 ... with-jack/
Audacity works over the top of both the audio system and Jack so you'll want those working first.
So, yes, it should be doable, but you may have to hack around in the audio system and Jack to do it.
Retired IT professional, C programmer and "beardie weirdie".
RPi interests: Developing an Infinite Improbability Drive
“Thinking outside of the box allows you to get rewards outside of your reach.” Matshona Dhliwayo