A size of a port hole in a package for a micro-electro-mechanical (MEMS) microphone can be modified to improve performance of the MEMS microphone while protecting the MEMS microphone from environmental interference. As an example, the port hole diameter is increased along a thickness of a substrate coupled to the MEMS microphone to reduce air mass loading and air flow resistance and thus, increase the resonant frequency, resonant peak, signal-to-noise ratio (SNR) and/or a range for flat frequency response of the MEMS microphone. In one aspect, the port hole can be created by mechanical and/or laser drilling. In another aspect, the port hole can be created by forming a cavity in the substrate over a drilled port hole.