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. 

1. Stolbov M.B. Application of microphone arrays for distant speech capture. Scientific and Technical Journal of Information Technologies, Mechanics and Optics, 2015, vol.15, no. 4, pp. 661–675. (In Russian) doi: 10.17586/2226-1494-2015-15-4-661-675
2. McCowan I.A. Microphone Arrays: A Tutorial. Available at: https://www.idiap.ch/~mccowan/arrays/tutorial.pdf (accessed 11.10.2015).
3. Singh H., Jha R.M. Trends in adaptive array processing. International Journal of Antennas and Propagation, 2012, vol. 2012, art. 361768. doi: 10.1155/2012/361768
4. Tashev I. Beamformer sensitivity to microphone manufacturing tolerances. Proc. 19th Int. Conf. on Systems for Automation of Engineering and Research, SAER-2005. Sofia, Bulgaria, 2005, pp. 132–136.
5. AIP Hand-book of Condenser Microphones: Theory, Calibration, and Measurements / Eds. G.S.K. Wong, T.F.W. Embleton. NY: American Institute of Physics, 1995, 322 p.
6. Nordholm S., Claesson I., Dahl M. Adaptive microphone array employing calibration signals: an analytical evaluation. IEEE Trans. on Speech and Audio Processing, 1996, vol. 7, no. 3, pp. 241–252. doi: 10.1109/89.759030
7. Seltzer M., Raj B. Calibration of microphone arrays for improved speech recognition. Technical Report TR-2002-43. Mitsubishi Research Laboratories.
8. Wu H., Jia Y., Bao Z. Direction finding and array calibration based on maximal set of nonredundant cumulants. Proc. IEEE Int. Conf. on Acoustics, Speech, and Signal Processing, ICASSP. Atlanta, USA, 1996, vol. 5, pp. 2626–2629.
9. Tashev I. Gain self-calibration procedure for microphone arrays. Proc. IEEE Int. Conf. on Multimedia and Expo, ICME. Taipei, Taiwan, 2004, vol. 2, pp. 983–986.
10. Krivosheikin A.V., Perelygin S.V. The principles of antenna arrays microphone settings. Materialy X Mezhdunarodnoi Nauchno-Prakticheskoi Konferentsii Prikladnye Nauchnye Razrabotki-2014 [Proc. X Int. Scientific-Practical Conference on Applied Research and Development 2014]. Prague, Czech Republic, 2014, pp. 14–17.
11. Krivosheikin A.V., Perelygin S.V. Microphone array for directional acoustic antenna implementation. Izv. vuzov. Priborostroenie, 2015, vol. 58, no. 3, pp. 221–225. (in Russian) doi: 10.17586/0021-3454-2015-58-3-221-225
12. Monzingo R.A., Miller T.W. Introduction to Adaptive Arrays. NY, John Wiley and Sons, 1980.
13. Krivosheykin A.V., Perelygin S.V. Microphone array modeling. Mir Tekhniki Kino, 2015, no. 1 (35), pp. 22–26.
14. Vahitov Sh.Ya., Kovalgin Yu.A., Fadeev A.A., Shchev'ev Yu.P. Acoustics. Moscow, Goryachaya Liniya - Telekom, 2009, 660 p.
15. Vahitov YaSh. Slukh i Rech' [Hearing and speech]. Leningrad, LIС Publ., 1973, 124 p.
 

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