I have a Teensy 3.2 and the Teensy audio board.
I was going to connect lavalier microphone to its audio jack but learned that it's only for output. There are line-in pins though (see "Back Side" scheme). And MIC+GND pins, but these are for, ehm, radio parts microphones, I guess?
Being a complete novice I have no idea how to connect microphone jack (or audio connector) to line-in pins and whether I would need an amplifier between microphone and pins. If so then probably I just can't do it.
I would be grateful for detailed instructions.