Electric compound action potentials (ECAPs) provide information about the nerve's and device's function in and after cochlear implantation. In general, lower ECAP values are expected to generate better results. Aim was an analysis of ECAPs in the course of time as a function of the patient's age and electrode design.

Between 2008 and 2013, 168 patients of eight defined age groups were included into the investigation. NRTs were measured intraoperatively, after 6 and after 12months.

The intraoperative mean value of ECAP was 174.14CL (current level) and decreased after 6months to 156.38CL. Highest ECAPs were achieved intraoperatively in the clusters “younger than 18months” (181.04CL) and “older than 80 years” (190.45CL). CI 422 showed apparently higher ECAP thresholds (182.69) during surgery than CI 24 RE (171.47) and CI 512 (170.64).

ECAPs are a well-established method to get information about the CI's and nerve's function during and after surgery. After initial higher values NRTs decrease after 6months and remain stable in the following controls. Very young and older patients tend to have higher thresholds than middle-aged groups. Perimodiolar electrodes are significantly attached to lower values because there is a closer nerve–electrode interaction.