The influence of masking on the ipsi- and contralateral brainstem evoked potential.

We have examined clinically and experimentally the masking effects of white noise in registering brainstem evoked potentials and determining the Jewett-wave V. We studied input-output functions as well as latency periods of evoked potentials with masking of non-stimulated contralateral ears in 18 children aged 5-14 years. When differences of 50 dB or more were found between stimulation and masking, the Jewett-wave V could be partially suppressed. Other changes observed included alterations in potential and phase, as well as shifts in the latency period of the potentials. The clinical importance of the measurements determined indicates that findings may be used in examining patients with unilateral sensory hearing impairments to formulate possible differential diagnoses.