ELECTRICAL MIDDLE-EAR MUSCLE-REFLEX - USE IN COCHLEAR IMPLANT PROGRAMMING

Programming of multichannel cochlear implants (Cls) requires subjectiv e responses to a series of sophisticated psychophysical percepts. It i s often difficult for young prelinguistically deaf children to provide adequate responses for device fitting. This is especially true in set ting levels of maximum comfortable loudness, whereby failure to indica te growth of loudness may result in elevation of stimulus levels to th e threshold of pain. The acoustic or stapedial muscle reflex has been used previously to provide objective confirmation of acoustic stimulat ion, anti there have been attempts to use the reflex in hearing aid fi tting. It has also been suggested that electrically elicited middle ea r muscle reflexes (eMEMR) may have applicability in confirming and qua ntifying electrical stimulation through a Cl. To assess the relationsh ip between eMEMR characteristics and levels of loudness perception wit h Cls, determine reliability of the response, and investigate potentia l use of eMEMR in Cl programming, 25 postlinguistically deafened adult Cl users were evaluated. Reflexes have also been attempted on 40 chil dren, with responses present in 31 (71%). Comfort levels predicted by eMEMR were highly correlated with those obtained through subjective ju dgments in the adult subjects. The eMEMR provides an objective, accura te, and rapid method of estimating maximum comfortable loudness levels , which may be useful in the initial programming of young implant reci pients.