Direction of Arrival Estimation for Speech Source Using Closely Spaced Microphones

Abstract

The direction of arrival (DoA) of an acoustic source is a salient parameter whose applications are diversified ranging from the defense industry to the entertainment industry. The conventional method of DoA estimation uses sensor (microphone or hydrophone) array with different computationally intensive algorithms, however, the size of sensor-array restricts its deployment in portable devices. The replacement of sensor-array is an acoustic vector sensor (AVS), which is compact in size and can be easily mounted on any small portable device. The AVS can be realized with omnidirectional microphones and/or particle velocity sensors. We have used different geometrical arrangements of closely spaced omnidirectional microphones (called AVS configurations) for determining the DoA of a speech source for real-time applications. The signals acquired by the closely spaced omnidirectional microphones are used to estimate the acoustic intensity vector, which gives the direction of an acoustic source. In this paper, we have given a method for DoA estimation of a broadband quasi-stationary source (speech signal) and compared the DoA estimation performance of different omnidirectional microphones based AVS configurations with the help of Finite Element Method tool, viz., COMSOL Multiphysics. The speech signals for different angular locations at different microphones of an AVS have been recorded using COMSOL Multiphysics modeling software.