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Unlabelled: Electrically Evoked Compound Action Potential is a measure of synchronous cochlear nerve fibers activity elicited by electrical stimulation of the cochlear implant. The electrophysiological nerve responses may contribute to explain the variability in individual performance of cochlear implant recipients., Aim: To compare speech perception tests performances of cochlear implant users according to the presence or absence of intraoperative neural telemetry responses., Material and Method: Prospective study design with 100 "Nucleus 24" cochlear implant users divided in two groups according to the presence or absence of intraoperative neural telemetry responses. Speech perception tests were performed after 6 months of continuous use of the device and compared among groups., Results: Intraoperative action potentials were observed in 72 % of individuals. Open-set sentence test results were better in implant users who had neural telemetry responses when compared to implant users in whom this potential was absent (averages 82.8 % versus 41 %, p = 0.005). There was a strong association between post meningitis-related deafness and absence of intraoperative potentials., Conclusion: The absence of intraoperative neural telemetry responses was associated with worse performances in speech perception tests and meningitis as etiology of deafness. On the other hand, the presence of these potentials suggests excellent prognosis.

Unlabelled: Cochlear implantation has been recommended for children under 24 months of age. The use of objective measures is needed to help speech processor programming. The electrically evoked compound potential (EAP), which can be assessed by neural response telemetry (NRT), is one of those objective measures., Aim: to determine how often the EAP can be recorded by NRT system during surgery and to describe the responses., Study Design: Clinical with transversal cohort., Material and Method: The impedances and NRT were measured in a group of 17 Nucleus 24 implant users. The responses were analyzed and compared to the etiology, hearing loss duration and electrode array position., Results: The EAP was easily recorded in the apical electrodes and, in otosclerosis and meningitis cases the EAP threshold was higher than in the other etiology cases., Conclusions: The NRT can be found in 82% of the cases during surgery. The responses obtained may vary according to etiology and the position of electrodes along the cochlea.