I think the first step would be to test if I can capture audio natively before I pass it through to GPIO. I've narrowed it down to wanting to use the alsa sound driver. I want to be able to hear the sound from my speakers while it's being captured which is looking like I'll need to use a loopback device. Eg snd-aloop I'll update this post when I have more details but I've gotten so far as sorting dependencies and just need the proper configs for /etc/.asound.conf