Objective: This study aims to determine if early device activation can influence cochlear implant electrode impedances by providing electrical stimulation within hours after cochlear implant surgery.
Design: Electrode impedances were measured intraoperatively, at device activation, and one-month after device activation in three groups: users whose devices were activated (1) on the same day (Same Day), (2) the next day (Next Day), and (3) 10-14 days (Standard), after cochlear implant surgery.
Study sample: Electrode impedances are reported in fifty-one patients implanted with a Cochlear™ Nucleus® Cochlear Implant.
Results: Compared to intraoperative levels, impedances dropped within hours for the Same Day activation group (p < 0.001) and continued dropping on the next day after surgery (p < 0.001). Similarly, electrode impedances were significantly (p < 0.001) lower at device activation for the Next Day group as compared to their intraoperative measurements. For Standard activation, impedances increased significantly from intraoperative levels, prior to device activation (p < 0.001). One-month after initial activation, impedances were not statistically different between the Same Day, Next Day, and Standard activation groups.
Conclusions: Early device activation does not influence long-term impedances in a clinically meaningful manner.
Keywords: Electrode impedances; cochlear implants; early activation; fluctuating impedances; next day activation; same day activation.