Was looking for exactly the same information and ran across the following: 2-mic and 4-mic linear array GPIO pins. I also added some information which may or may not be of use to you. Good luck with your project! 
Was looking for exactly the same information and ran across the following: 2-mic and 4-mic linear array GPIO pins. I also added some information which may or may not be of use to you. Good luck with your project!