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Multiple Source Localization with Distributed Tetrahedral Microphone Arrays

Authors Hack, P.
Year 2015
Thesis Type Master's thesis
Topic Spatial Audio
Abstract Microphone arrays have many different application areas and allow to analyze complex sound fields. This work focuses on acoustic source localization. In contrast to a central microphone array, which samples the sound field only locally and hence is limited to Direction of Arrival (DOA) estimation, distributed microphone arrays enable the estimation of absolute source positions in space. In this work, multiple distributed tetrahedral microphone arrays are used, where each tetrahedral array is able to estimate the DOA in 3 dimensions based on an intensity vector approach. By means of triangulation, the DOA estimates of the individual arrays can be integrated to a resulting source position estimate. Two different localization algorithms are developed, which are robust to sample clock synchronization mismatches among the arrays (important for wireless systems) and which provide the estimation of absolute source positions in 3D for single and multiple source scenarios. To evaluate the two algorithms real-world measurements are conducted, illuminating the effect of the number of used tetrahedral arrays on the localization performance. For optimal accuracy the DOA estimation performance of the Oktava 4D-Ambient tetrahedral arrays is improved by measurements and a DOA error-correction dictionary.
Supervisors Zotter, F., Zaunschirm, M., Schörkhuber, C.