Microphone assembly with back volume vent

A microphone assembly comprising:

• a substrate having a port formed therein;
• a MEMS acoustic transducer that is pierce-less coupled to the substrate, disposed over the port, the MEMS acoustic transducer comprising:
• a back plate;
• and
• a diaphragm structured to vibrate in response to pressure changes through the port, the back plate and diaphragm together forming a capacitor having a capacitance that changes responsive to movement of the diaphragm;
• an integrated circuit coupled to the substrate configured to generate an electrical signal representative of acoustic activity based on changes in capacitance between the diaphragm and the back plate of the MEMS acoustic transducer;
• a cover coupled to the substrate, comprising a first aperture;
• and
• an aperture reduction structure comprising a second aperture and coupled to the cover overlapping the first aperture, wherein the second aperture is smaller than the first aperture, and wherein the second aperture overlaps the first aperture.

A method of forming a microphone assembly, the method comprising:

• providing a substrate having a port formed therein;
• coupling an acoustic transducer to a first surface of the substrate, wherein the acoustic transducer is disposed over the port;
• coupling a cover to the first surface of the substrate, the cover comprising a first aperture;
• removing contaminants from the back volume through the first aperture during coupling of the cover to the first surface of the substrate;
• and
• coupling an aperture reduction structure to the cover at a position overlapping the first aperture after removing the contaminants, the aperture reduction structure comprising a second aperture smaller than the first aperture, wherein the second aperture overlaps the first aperture.