Clinical Research Directory

Inclusion Criteria: * Male or female 22 to 80 years of age. * Able to complete study related procedures. * Able to provide written informed consent. * Eligible for cochlear implant surgery as per routine pre-operative CI evaluation/workup. If patient is a candidate for bilateral CI, the research technique will be performed unilaterally on the side with the most favorable anatomy and/or worst residual hearing. * Pre-operative CT scan of head/temporal bone as part of routine care showing normal temporal bone and intra-cochlear anatomy. * Scheduled to receive either a Cochlear CI522 with the slim straight electrode or a MED-EL Synchrony with standard, Flex 24, or Flex 28 electrode. Exclusion Criteria: * Females who are pregnant. As part of routine pre-operative care, all females of childbearing potential will undergo either urine or blood pregnancy testing. * ASA (American Society of Anesthesiologists) Physical Status classification of 4 or above or determined by surgeon to be too great of a health risk. * Previous mastoidectomy on the ear undergoing research procedures. * Severe anatomical abnormality of the temporal bone including but not limited to: 1) Mondini malformation 2) common cavity malformation 3) enlarged vestibular aqueducts (EVA) and/or 4) cochlea ossification. * Severe chronic ear disease. * Active middle ear infection. * Subjects without a favorable trajectory based on pre-operative imaging, analysis and planning with favorable trajectory defined as a linear track extending from the surface of the mastoid cortex, through the facial recess, and targeting the basal turn of the cochlea without violation of the external auditory canal, sigmoid sinus, tegmen, and/or facial nerve.