Optimal electrode design: Straight versus perimodiolar

The electrode in a cochlear implant (CI) system is a key factor in hearing performance as it is the interface between the device and the auditory pathway of the recipient. The first CI electrodes were straight and thus adopted a lateral wall position. Subsequent innovations include: perimodiolar electrodes designed to lie adjacent to the modiolar wall and thus to provide more spatially-focused stimulation of the spiral ganglion cells; shorter atraumatic straight electrodes for combined electric and acoustic (hybrid) stimulation. This paper explores the relative merits of straight and perimodiolar electrodes in the search for the optimal electrode design with reference to electrodes from Cochlear(®).