Localisation of Multiple Sounds as a Function of the Duration of the Inter-Sound Gap

One issue that arises in relation to the use of three-dimensional audio displays as a means of conveying spatial information to human operators concerns the ability of operators to track the locations of multiple sounds. We have examined the effect of varying the gap between a target and five distracter sounds on the accuracy with which the target sound can be localised under conditions in which participants were informed of the identity of the target sound after stimulus presentation. Inter-sound gap durations of 50, 100, 200, 400, 800 and 1600 ms were employed. Localisation performance was observed to improve as gap duration increased but was generally poor in comparison to that associated with localisation of the target sounds in the absence of the distracter sounds.