The evaluation of the functionality of the CI is facilitated by several analysis tools, such as the clinical calibration software. This offers the possibility of measuring electrical impedances in the cochlea. The electrical impedance is the opposition to the current flow between two electrodes. It is composed of two main elements: resistance and reactance. The impedances in a cochlear implant are not stable over time. The value is minimal immediately after surgery, and increases progressively in the first 2 to 3 weeks after the procedure due to the immune response of the organism against a foreign body and the trauma of the array insertion. Several authors have suggested the use of topical or intravenous corticosteroids to decrease intracochlear fibrosis. The use of Dexamethasone could have a protective effect by reducing the initial inflammatory response, apoptosis, and delayed fibrosis, which could impact the impedance.