Enhanced modiolar stimulation effects in the inferior colliculus

Both a perceived low frequency shift by cochlear implant patients in response to high stimulus levels and a perceived lower pitch for place of electrical stimulation have previously been described when compared with acoustic stimulation on the opposite side. Modiolar stimulation is likely the cause. This preliminary study quantifies and provides one explanation for the extent of modiolar stimulation observed as a function of current level as recorded in a population of inferior colliculus units. The inferior colliculus units were driven by scala tympani bipolar charge balanced stimulation.