Binaural direction-of-arrival estimation in reverberant environments using the direct-path dominance test

Speaker localization in reverberant environments is currently an important challenge in audio signal processing, and several methods have recently been proposed to address it. One such family of methods is based on the direct-path dominance (DPD) test that was developed specifically for spherical arrays and recently extended to arbitrary arrays. In this paper, an extension of the DPD test for a binaural array is examined. This extension uses a focusing technique to remove the frequency dependence of the steering matrix within frequency bands. This facilitates frequency smoothing, which is necessary for decorrelating coherent reflections. Unlike other focusing approaches, the proposed focusing approach does not rely on the initial estimation of source directions, facilitating its application in reverberant environments. However, in the binaural case, there is no guarantee of focusing performance. This paper presents an analysis of this focusing process for the binaural case and shows that good focusing performance can be obtained in the binaural case. A simulation study examines the effect of the focusing and smoothing and demonstrates the proposed method's capabilities in overcoming adverse reverberation conditions.