Effects of head movement on distance localization of sound image

To clarify the effect of head movement on distance perception of sound images, distance perception experiments were conducted under head-still and head-moving conditions by randomly presenting stimuli of different sound pressure levels from several distances. The A-weighted sound pressure levels of the stimuli were 40, 35, and 30 dB at the center of the head, regardless of the distance at which the sounds were presented. The stimuli were presented from 20 to 160 cm from the center of the head, and the presented direction was frontal or diagonally front. In the frontal head-still condition, the perceived distance was approximately constant for the same listening level, with higher levels perceived closer and lower levels perceived further away. In the diagonal head-still condition, differences in distance were more perceptible compared to the frontal condition; however, lower levels of near-distance stimuli tended to be perceived further away. By comparison, in the head moving condition, the distance localization accuracies improved. In particular, the mean response and presentation distances were almost the same in both directions in the range of 20–60 cm. Therefore, it was found that head movement had a positive impact on sound image distance perception.