Averaged electrode voltages used to identify nonfunctioning electrodes in cochlear implants: case study

We present the case of an adult male whose internal cochlear implant unit failed. Several months elapsed following initial stimulation with the implant before the problem was identified and corrected. The sequence of the failure and its detection are detailed. Following reimplantation, the patient did not initially report improved sound quality. However, within a week of the initial stimulation of the second device, he reported being able to identify environmental sounds, and speech began to sound the way he remembered it before he lost his hearing. We suggest a method of detection that might improve the early identification of a nonfunctioning device or of nonfunctioning individual electrodes. Knowledge of specific nonfunctioning electrodes is important in device adjustment, especially for young children.