Abstract
Brainstem electric responses (BSER) were recorded simultaneously to give records which were ipsilateral and contralateral to the test ear. Eight normally hearing subjects were presented with a fixed stimulus level in one ear and various levels of masking in the other ear. Responses to binaural stimulation were also recorded. It appears from the analysis of results that, for normal subjects, contralateral masking has no statistically significant effect upon the BSER. For the responses obtained from the stimulated side the analyses of variance showed a significant subject effect but no significant masking level effect from 0 to 80 dB Sensation Level of masking. For the responses obtained from the masked side the same conclusions seem to apply. As contralateral masking has no adverse effect upon the BSER in normal subjects and has had considerable use on clinical patients, with no significant problem, the normal audiometric use of masking is recommended for BSER recording.