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TitleLow frequency phase calibration for a circular microphone array
Publication TypeConference Paper
Year of Publication2007
AuthorsTeal, P.D., and Poletti M.A.
Conference NameICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Date Published2007
KeywordsAcoustic arrays, Calibration, Frequency response, Holography, Microphones, Mid-range frequencies, Multipath propagation, Phase calibration, Phase mismatch, Sound recording
AbstractPrevious work has indicated that a limitation on the low frequency performance of a circular microphone array for holographic sound field recording is phase mismatch between the microphones in the array. At low frequencies these variations become more significant than at mid-range and high frequencies because the high order phase mode responses are lower in amplitude. This paper investigates the possibility of performing a "self" calibration of a microphone array. The basis of the calibration is to estimate the location of one or more sources using mid-range frequencies and to use this source location information to perform, correction to the array at low frequencies. This of course implies that the calibration is performed in a relatively anechoic environment, since multipath effects at widely differing frequencies are uncorrected. Initial results confirm that a significant improvement in the array response is possible using this approach. © 2007 IEEE.

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