Towards Blind Localization of Room Reflections with Arbitrary Microphone Arrays

Blind estimation of the direction of arrival (DOA) of early room reflections, without a priori knowledge of the room impulse response or of the source signal, may be beneficial in many applications. Recently, a method denoted PHALCOR (PHase ALigned CORrelation) was developed for DOA estimation of early reflections, which displayed superior performance compared to previous methods. However, PHALCOR was developed and evaluated only for spherical microphone arrays with a frequency-independent steering matrix, with input signals in the spherical harmonics domain. This paper extends the formulation of PHALCOR by introducing a focusing process that removes the frequency dependence of the steering matrix, and provides performance analysis of the estimation of the recorded signal from a spherical array, operating in the microphone signals domain, compared to the performance of PHALCOR, operating on signals in the spherical harmonics domain.