A MEMS microphone assembly includes a MEMS transducer element having a back plate and a diaphragm displaceable relative to the back plate. A bias voltage generator is adapted to provide a DC bias voltage applicable between the diaphragm and the back plate. An amplifier receives an electrical signal from the MEMS transducer element and provides an output signal. The amplifier is adapted to amplify the electrical signal from the MEMS transducer element according to an amplifier gain setting. A processor is adapted to carry out a calibration routine at power-on of the microphone assembly determining information regarding the DC bias voltage and/or the amplifier gain setting.