Effect of microphones non-identity on the microphone arrays characteristics

Subject of Research. The paper deals with known methods that ensure microphone channels matching in a microphone arrays.The authors have developed the new calculation method of the sensitivities difference of the microphones having an effect on interfering signal suppression in the problem of broadband signals spatial separation.Methods. Theoretical and experimental studies are based on the use of the discrete Fourier transform apparatus, methods of computational mathematics, mathematical modeling. Main Results. We have proposed analytical expressions in a closed form and theoretical dependences, linking the degree of the interfering signal suppression with the microphones sensitivities difference. Simulation, performed in MATLAB environment (version 7), has confirmed the validity of theoretical results. In the course of modeling the authors have obtained experimental dependence of the interfering signal suppression on the microphones sensitivities difference. This dependence gives the possibility to define a tolerance on a difference between microphones frequency responses, which guarantees the required interfering signal suppression at the useful signal selection. Practical Significance. The results can be applied in the design of the device which separates target speaker's speech from noise of a mixture of voices.