Cochlear implants (CI) are a computerized device which provides people presented with severe and deep hearing loss with greater communication ability. Taking into account that the acoustic signal processing takes place in the sub-cortical and cortical areas, the electrophysiological evaluation of the central auditory processing may be a differential indicator for the speech perception performance with the CI, since it provides objective parameters of the auditory processing. Such parameters may contribute to the understanding of speech-perception performance differences found among CI users when compared as to: sort of CI, insertion of electrodes in the cochlea, coding strategy and mode of stimulation. Thus, the present study aims at evaluating the auditory processing in multichannel CI users to verify whether the differences in their speech perception performance reflect upon the quality of Cognitive or event-related potentials (P300), generated from linguistic stimuli. Speech perception performance will be assessed through the following procedures: Gasp adapted for 5-year old children (Bevilacqua & Tech, 1996); List of dissylable vocables (Bevilacqua & Delgado); List of monossylables (Lacerda, 1976). The study will be carried out at the Speech Pathology Clinic at the Dental School of the University of São Paulo at Bauru, and the Audiological Research Center (CPA) with the Craniofacial Anomalies Rehabilitation Hospital (HRAC). The cognitive potentials will be recorded by means of electrodes positioned in regions Cz/Fz/M1/M2 of the skull and connected to the Biologic Evoked Potential System (EP), by cables. Thirty subjects users of multichannel CI for over 6 months, above 7 years of age and well adapted will be screened to comprise the experimental group. The control group will be comprised of normal subjects, compared to the experimental group as for the number, gender and age, with no history of risk for auditory, language and neurological alterations. To perform the P300, the subjects (control and experimental groups) will remain in dorsal decubitus, submitted to two speech stimuli: one rare or infrequent and another continuous our infrequent, in a randomly selected proportion by the Biologic Evoked Potential System. Subjects will be asked to remain alert to the infrequent stimulus and to perform the simple motor gesture every time they hear it (raise their hand).
News published in Agência FAPESP Newsletter about the scholarship: