Interaural latency differences for wave V (IT) were measured for 406 patients having cochlear hearing loss and for 36 patients with Vlll th nerve tumors. The incidence of IT5 values exceeding 0.2, 03, and 0.4 msec was plotted as a function of the degree of asymmetry in hearing sensitivity for 2,000—4,000 Hz. In general, the patients with cochlear hearing loss and the greatest degree of hearing asymmetry yielded IT5 values that exceeded 0.2, 03, or 0.4 msec more frequently than patients with more symmetric hearing losses, and this trend was apparent for all degrees of hearing loss. For the Vlllth nerve tumor patients, IT5 data were scattered widely regardless of symmetry or asymmetry of hearing sensitivity. The falsenegative rate was 8% when IT5 was greater than 0.4 msec.