Improvement in estimation accuracy of a sound source direction by a frequency domain binaural model with information on listener´s head movement in a conversation

Estimation of sound source directions and separation of sound sources are implemented on many products widely, and binaural hearing aids are one of its applications. In a conversation using a binaural hearing aid, continuous tracking of sound sources with acoustics signals are sometimes complicated because sound sources move dynamically. In order to make the tracking of sound sources simple, it is considered to be helpful to use non-verbal information in communication. Since a user´s body movement, including a head, corresponds to speakers´ positions, it is possible to estimate communication zone where sound sources locate by a head direction. In this paper, a head movement in a conversation, as non-verbal information in communication, is measured and discussed. A rotational angle of a head movement is estimated by an inertial sensor which has an accelerometer, angular velocity sensor, and a magnetic field sensor with attaching to left ear position. A relationship between a head movement and directions of sound sources during a conversation by multiple speakers is presented. The results indicate a possibility for estimating a communication zone.