Suitable spatial resolution at frequency bands based on variances of phase differences for real-time talker localization

Conventional near-field talker localization methods with microphone-array calculate spatial spectrum in each scanning position of discretized space and each frequency. Hence, elapsed time is increased and real-time processing is difficult. Real-time processing is important for achieving the natural interaction with the speech interfaces. To overcome this problem, we newly propose a talker localization method based on Multi-resolution Scanning in Frequency Domain (MSFD). MSFD utilizes lower spatial resolution in the lower frequency band and higher spatial resolution in the higher frequency band to reduce elapsed time. We also propose a calculation method for suitable spatial resolution at each frequency on the basis of the variances of phase differences among microphones. The results of evaluation experiment indicated that the proposed MSFD could reduce the elapsed time without degrading the localization accuracy.