  The proposed Circular statistics-based Inter-Microphone Phase difference
estimation Localizer (CIMPL) method is tailored toward binaural hearing aid
systems with microphone arrays in each unit. The method utilizes the circular
statistics (circular mean and circular variance) of inter-microphone phase
difference (IPD) across different microphone pairs. These IPDs are firstly
mapped to time delays through a variance-weighted linear fit, then mapped to
azimuth direction-of-arrival (DoA) and lastly information of different
microphone pairs is combined. The variance is carried through the different
transformations and acts as a reliability index of the estimated angle. Both
the resulting angle and variance are fed into a wrapped Kalman filter, which
provides a smoothed estimate of the DoA. The proposed method improves the
accuracy of the tracked angle of a single moving source compared with the
benchmark method provided by the LOCATA challenge, and it runs approximately 75
times faster.
