(a) Configuration of the head tracking system with a single primary loudspeaker. The tracking system and the LDV are placed to the left side of the head. (b) The construction of the tracking system with a pan and a tilt mirror for steering the laser beam. The camera is attached to the controller for the target object tracking. (c) A yellow marker is placed below the membrane on the ear lobule as the target object. (d) Schematic of the camera-based tracking system showing the laser beam path from the scanning LDV.