Design Study on Microphone Arrays

This paper presents a design of microphone array system that is intended for conference room applications. Different microphone array configurations have been considered in this work to demonstrate the importance of array layout. The filter-and-sum broadband beamformer is designed by using weighted least square (WLS) optimization method. As existing near-field broadband beamformers are sensitive to changes in microphone characteristics and position, robust designs need to be considered that include microphone characteristics mismatch (gain and phase) in the design. Furthermore, it is shown that the aperture size is important for the designed beamformer performance. Golden section search technique is used to find optimal aperture size and weights. The important roles that microphone array layout, robust design and aperture size play in the design of the broadband beamformer are demonstrated.