Language laterality assessed by unilateral ECT and dichotic monitoring.

A dichotic monitoring test for the lateralisation of speech dominance was compared with testing for dysphasia after unilateral electroconvulsive therapy to each side of the head in 31 patients, and the intracarotid amylobarbitone test in four epileptic patients. Twenty-eight patients shown to be left speech dominant also showed right ear advantages in the dichotic test. Four of the five right speech dominant patients showed left ear advantages. Two patients with bilateral speech representation showed nonsignificant ear asymmetries. The noninvasive dichotic monitoring task is quick and simple and produces large mean ear advantages (14 to 25%) in normal subjects as well as patients.