DOA Estimation of Multiple Speech Sources from a Stereophonic Mixture in Underdetermined Case

Ning DING  Nozomu HAMADA  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E95-A   No.4   pp.735-744
Publication Date: 2012/04/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E95.A.735
Print ISSN: 0916-8508
Type of Manuscript: PAPER
Category: Engineering Acoustics
direction of arrival,  time-frequency representation,  reliability index,  statistical model,  kernel density estimator,  

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This paper proposes a direction-of-arrival (DOA) estimation method of multiple speech sources from a stereophonic mixture in an underdetermined case where the number of sources exceeds the number of sensors. The method relies on the sparseness of speech signals in time-frequency (T-F) domain representation which means multiple independent speakers have a small overlap. At first, a selection of T-F cells bearing reliable spatial information is proposed by an introduced reliability index which is defined by the estimated interaural phase difference at each T-F cell. Then, a statistical error propagation model between the phase difference at T-F cell and its consequent DOA is introduced. By employing this model and the sparseness in T-F domain the DOA estimation problem is altered to obtaining local peaks of probability density function of DOA. Finally the kernel density estimator approach based on the proposed statistical model is applied. The performance of the proposed method is assessed by conducted experiments. Our method outperforms others both in accuracy for real observed data and in robustness for simulation with additional diffused noise.