LATERALIZATION OF CLICK-TRAINS WITH OPPOSING ONSET AND ONGOING INTERAURAL DELAYS

Lateralization of a click-train containing 200 clicks was examined in a two-interval, forced-choice design. The first of two intervals consi sted of a diotic reference train while the second interval contained t he test train. The initial click of the test train carried an interaul e time difference (ITD) favouring one ear and the interaural delay of subsequent clicks were reversed. Subjects were instructed to identify the side to which the test-train was lateralized (right or left) relat ive to the reference. Data were organized in terms of the percentage o f times the test-train was lateralized to the same side as the ear whi ch favoured the onset click. Short interclick intervals (ICI<2 ms) res ulted in high percentages and long ICIs (>4 ms) resulted in small perc entages. Subjective reports indicated a single fused image for short a nd long ICIs, and the presence of two concurrent percepts for intermed iate ICIs during the presentation of the test stimulus.