Within a simulated air traffic control task, improvement in the detection of auditory warnings when using virtual 3-D audio depended on the spatial configuration of the sounds. Performance improved substantially when 2 sources were placed to the left and the 2 were placed to the right of the participant. Unexpectedly, little benefit was observed for configurations involving the elevation or transverse dimensions of virtual space, suggesting that position on the interaural axis is the crucial factor to consider in auditory display design. Relative importance of interaural spacing effects was corroborated in a 2nd, free-field experiment. Two additional experiments showed that: positioning signals to the side of a listener is superior to placing them in front, even when 2 sounds are presented in the same location; and the optimal distance on the interaural axis varies with the amplitude of the sounds. This suggests that guidelines for auditory display design that allow for effective perception of speech information can be developed from an analysis of the physical sound patterns. (Author/publisher)
Abstract