This talk presents the development of several microelectromechanical systems (MEMS)-based acoustic transducer technologies for fluid mechanics and aeroacoustics applications. Specifically, this presentation will focus on several aluminum nitride piezoelectric MEMS dynamic pressure sensors and microphones. These devices offer the promise of reducing cost, improving performance, and increasing mounting flexibility over existing conventional microphone technologies. Specifically, a transducer with no external power requirement has a key advantage for a large-channel count, widespread deployment. The modeling and design aspects of these devices are reviewed. First, the electroacoustic transduction is predicted via piezoelectric composite plate theory. Lumped element models are then synthesized to describe the dynamic characteristics of the transducer diaphragm and the cavity/vent structure. Constrained nonlinear design optimization using a sequential quadratic programming scheme is then performed to determine the design parameters. Representative results for several applications will then be presented. Finally, unresolved technical issues are summarized for future sensor development.