Auditory Facing Angle Perception: The Effect of Different Source Positions in a Real and an Anechoic Environment

In social interaction it is vitally important to be able to perceive the gaze direction or the head orientation of the people talking around us. As long as our dialogue partner is within our field of vision, visual cues are normally responsible for the head orientation estimation, here termed facing angle. The facing angle describes the angle of orientation for a directional source relative to the receiver position. The aim of this study was to measure the ability of participants to estimate the facing angle of a directional sound source based on acoustic cues for facing angles in 25° steps at three source positions (frontal, lateral, rear left) in an anechoic and reverberant environment. The listeners performed generally poorly for a lateral or rear left sound source compared to a frontal sound source. They showed the best performance when the sound source pointed directly to the listener for all tested source positions. However, listeners perceived small facing angles as direct-facing. The facing angle estimation was more difficult in the anechoic room for facing angles where the loudspeaker was turned away from the listener. For a lateral sound source, the listeners were partly unable to distinguish between positive and negative facing angles.