I have a question about interpretation of the signal produced by a microphone.
The output of a microphone is a voltage level that corresponds to the pressure on the membrane. The part that confuses me is why are the output signal values located above and below the average (picture attached). Do the values "above and below" correspond to the membrane deflecting, and then going back to its original position? If that's the case, should I just concider the values above the average for my further computation of the Fft?