Abstract
To investigate the performance of sound source localization in the front-middle plane at arbitrary body positional angles, a mobile three-D acoustic stimulator was developed. The angle of the body position is adjustable in parallel with the sound sources that are arranged around the subjects. In the present study, 4 identical speakers were arranged in the front-middle plane of the subject. The speakers were separated by 9 degrees in the vertical plane. Using a white noise tone (0.3-s duration), a sound source discrimination task was conducted in five body positions at 90-, 67.5-, 45-, 22.5- and 0-degree angles. As a result, the average of the correct response rate was higher in the 90- and 0-degree body positions than that in the 67.5-, 45- and 22.5-degree body positions. The localization of the source position tended to be distorted (skewed) to the middle (eye) level in all body positions. The vertical distortion to the middle (eye) level became large in the 67.5-, 45- and 22.5-degree body positions compared to that in the 90- and 0-degree body positions. These results suggest that sound source localization in the front-middle plane is affected not only by the body position but also by the vertical sound position.
