a microphone assembly include a microphone housing unit having a cover and a base . the microphone assembly further includes a preamplifier circuit assembly attached to the base and protected by the cover . the protected preamplifier circuit assembly has at least one terminal unprotected by the cover . a radio frequency interference suppression device can be electrically coupled to the preamplifier circuit and includes at least one internal ground electrically coupled to the at least one terminal . the at least one internal ground provides a ground path between the cover and the base .