Figure 1.

Examples of an ITD-discrimination trial. A, For BI-CI subjects, a two-interval, two-alternative forced-choice left/right discrimination task required the subject to determine whether the two stimuli were played left then right or right then left. B, For SSD-CI subjects, the left/right discrimination task proved too difficult given the inherent time delay between the ears. Therefore, a three-interval, two-alternative forced-choice task was used, which required the subject to determine whether the second or third interval contained a moving set of stimuli.