intraindividual comparison of psychophysical parameters between perimodiolar and lateraltype electrode arrays in patients with bilateral cochlear implants objective perimodiolar electrode arrays were developed to improve stimulation of specific neuronal populations and to decrease power consumption however they can damage the cochlear structure we examined and compared psychophysical parameters of perimodiolar and lateraltype electrode arrays in patients who received a different type of bilateral cochlear implant ci in each earstudy design retrospective analysissetting tertiary referral centerpatients eight child patients three males five females received a different ci in each ear perimodiolar array and lateral array they received the cis sequentially n 7 or simultaneously n 1interventions diagnostic therapeutic and rehabilitativemain outcome measures electrically evoked compound action potential threshold level comfort level and dynamic range dr of the basal mid and apical electrodes were compared we also surveyed battery consumption for each deviceresults electrically evoked compound action potential threshold threshold level and comfort level were lower for the perimodiolartype electrode array than for the lateraltype electrode array in most patients however the dr for the perimodiolar array was narrower than for the lateral array for most patients there was little difference in battery lifeconclusion although the level of electrical energy required for auditory stimulation seems to be lower for the perimodiolar electrode array than for the laterally placed array the dr was wider and the amount of battery consumption was similar the electrode array should be chosen by considering various patient factors such as residual hearing