Estimating the performance of a superdirective microphone array with a frequency-invariant response

The knowledge of the impact of sensors tolerances in the beamformer performance is of crucial importance in many design cases, especially when superdirective arrays are employed. The availability of the array characteristics (i.e. perturbations on sensors responses and elements displacement), allows to obtain an expectation of the system capabilities corrupted by realistic imperfections. In this paper we discuss the effectiveness of the expected beam pattern as an a priori criterion for the beamformer performance estimation. In particular, the expected beam power pattern has been compared to the actual one, resulted from an experimental investigation of a superdirective microphone array. The tight adherence between the two beam shapes accounts for the effectiveness of the proposed tool in driving the system design.