In an EP study, EEG-like recording electrodes are placed on your child's scalp that stimulate the appropriate pathways. Visual evoked potentials are done by either looking at a changing checkerboard pattern or at a flashing light. Auditory evoked potentials are done by stimulating the auditory system with a clicking noise. Special auditory EP techniques allow a determination of whether poor hearing results from inner ear, nerve to the ear, or brain problems. Somatosensory evoked potentials are done by giving a small electrical impulse to the extremities. Your child might require sedation for an EP.