Aeroacoustic testing capability in both anechoic and hard-walled facilities has grown tremendously over the last decade. Such testing has provided successful collection of noise source location and directivity data in facilities such as Quiet Flow Facilities, and other subsonic, low, and high speed tunnels. One of the reasons for the success of these measurements has been the development of both phased microphone array instrumentation and robust data processing algorithms/software used in the analysis of acquired array data. While the gains using microphone arrays has been significant, several challenges must be overcome before fully realizing the potential of this technology. Most important among these challenges is the need to extend classical beam-forming techniques, incoherent monopole source theory, to more robust algorithms based on higher-order (i.e., multipole) models of the source to be measured. However, implementation of new multipole-based algorithms will require a change in thinking about how microphone arrays are constructed and operated.