Record audio from two microphones at the same time

Is it possible through some c# library, plugin, or external hardware, to record two microphones at the same time. I’m looking for a solution that would work for windows standalones, or for ios.

You should look here in the unity docs. Basically you can get a list of the names of all the microphones attached to your system. A device name can then be used as an argument in functions to start and stop recording.