[Audiometric threshold shift in patients with cochlear implantation]

A great number of studies have been carried out during many years in order to evaluate the histological changes that take place after the insertion of a cochlear implant, having been experimentally and histologically, in temporal bones, demonstrated its relative harmlessness. We have focused our functional investigation induced by the implants through the shift of pre- and postoperative tonal audiometric thresholds, in 13 carriers on an C. I. Nucleus 22. Most of them suffered minimal or even showed no shift of thresholds. Therefore we consider the functional alterations due to the insertion of electrodes as practically nonexistent.