[Effects of head movements on sound localization in pseudo-phonically reversed hearing]

Measurements of sound localization in the lateral dimension were taken with or without head movements when the observer wore the electronic pseudophone in an anechoic chamber. Tones of various frequencies as stimuli were presented from the loudspeakers located on the horizontal plane of the observer's head and on the circle, 2 m in diameter, around the observer, who pointed with his hand the position from which he thought the sound originated. The results of three subjects showed that: when the inter-aural axis of the pseudophone was 180 degrees reversed, real and apparent locations of the sound were symmetrical with respect to the median of the observer's head under the head-fixed condition, but were symmetrical with respect to the position of the observer's head as a center under the head-free condition. The implication of the results obtained was discussed.