Increasing the power of dichotic methods: the fused rhymed words test.

A dichotic test made up of monosyllabic rhymed CVC words was modified to minimize stimulus dominance and errors and then administered to 194 dextrals and 175 sinistrals in four different laboratories. The proportion of subjects with left ear advantages in both the right and left-handed groups closely approximated that expected from neurologic data. This dichotic test appears to reflect hemispheric specialization for language function more accurately than previously available tests. Further direct validation studies are needed, however, comparing direction of ear asymmetry and other indices of hemispheric specialization for language on a subject by subject basis.