A microphone assembly comprises a substrate. An acoustic transducer is disposed on the substrate and configured to generate an electrical signal responsive to an acoustic signal. An integrated circuit is disposed on the substrate and electrically coupled to the acoustic transducer. An enclosure is disposed on the substrate, and comprises a main body, and a sidewall projecting axially from outer edges of the main body towards the substrate and contacting the substrate such that an internal volume is defined between the enclosure and the substrate. An insulating layer is insert molded on an inner surface of the enclosure, or over molded on an outer surface of the enclosure such that the insulating layer is not disposed on a portion of the sidewall proximate to the substrate.