Mismatch negativity (MMN): indexing auditory discrimination in cochlear implants

Background: Cochlear implants (CIs) can be used effectively in the profoundly impaired children. However, they show great variability in their outcomes and performance in the rehabilitation program. This variability could be related to the underlying temporal processing variability in those children. Objectives: To assess fine auditory discrimination in children fitted with CIs. Methods: Mismatch negativity (MMN) was recorded in 20 children fitted with unilateral CIs. MMN was recorded in two tones paradigms using 1000 Hz, 4000 Hz and one speech paradigm using speech syllables. Results: Children fitted with CI have good MMN that morphologically similar to that recorded in normal hearing peers, however, with delayed latencies. There was also a good correlation between MMN response and duration of CI use. Conclusion: MMN can be used as good new diagnostic AEPs for the assessment of fine discrimination in CIs users. So, MMN provides for further efforts for improving CI design and speech strategy and monitor recipients' results in rehabilitation program.