So you mean I’ll need to insert a cap to reduce the noise on the input voltage - to isolate the microphone response?
Noooo, check the schematics, I hope you can read them. The microphone output and the board input is not connected directly, they have a small capacitor (probably ceramic or other nonpolarized, 10-100 nF) inbetween, in series, so the signal DIFFERENCE (the dv in physics language) goes on the mic input.