Abstract
In this paper, we present three approaches to localizing and tracking a sound source moving in a three-dimensional (3D) space using a bi-microphone array rotating at a fixed angular velocity. The motion of the sound source along with the rotation of the bi-microphone array results in a sinusoidal inter-channel time difference (ICTD) signal with time-varying amplitude and phase. Two state-space models were employed to develop extended Kalman filters (EKFs) that identify instantaneous amplitude and phase of the signal. Observability analysis of the two state-space models was conducted to reveal singularities. We also developed a method based on Hilbert transform, which is done by comparing the analytic signal of the true ICTD signal with that of a virtual signal having zero elevation and azimuth angles. A moving average filter is then applied to reduce the noise and the effect of the artifacts at the beginning and the ending portion of the estimates. The effectiveness of the proposed methods was tested and comparison studies were conducted in the simulation.
