Modeling Virtual Channels in Cochlear Implant Systems

Simultaneous electrical stimulation of neighboring electrodes generates channel interaction, which is generally undesirable. However, it is possible to create virtual channels or virtual electrodes by stimulating two neighboring electrodes in a suitable manner. In this paper, the ratio of the magnitude of voltage applied to two neighboring electrodes was adjusted according to: 4:0, 3:1, 2:2, 1:3, 0:4. Our model was created by coupling an Ineraid electrode array with a half turn of a human cochlea finite element model. The five different conditions generate five different activating function peaks along the Basilar membrane and between the electrodes, representing five different pitches as perceive by the cochlear implant users. The modeling result is consistent with experimental result