Electrophysiological responses in relation to speech perception in children with cochlear implants

Abstract Background Speech perception is a critical outcome of pediatric cochlear implantation, reflecting the effectiveness of auditory signal transmission and cortical processing for functional communication. Objective electrophysiological measures may provide valuable insight into neural discrimination and cortical auditory encoding, particularly when behavioral assessments are constrained or unreliable. Objective This study aimed to examine the relationship between objective electrophysiological measures and speech perception ability in pediatric CI users and to explore the potential complementary value of MMN and CAEPs in assessing auditory cortical processing. Methods This study included a control group (20 normal-hearing children) and a study group (46 children fitted with unilateral CI that were matched in age and gender. The study group was classified into two subgroups based on speech discrimination score (SD%). Subgroup 1 (SD1) included 17 CI children who had SD ≤ 60%, while subgroup 2 (SD2) consisted of 29 CI children who had SD > 60%. They were assessed through detailed history taking, otoscopic examination, basic audiological evaluation, mismatch negativity, and cortical auditory evoked potentials. Results MMN was absent in 13 CI children. No significant differences were found in MMN latency or amplitude among the SD1, SD2, and control groups. Significant group differences were observed in P1, N1, and P2 latencies, while N2 latency was not significantly different. N2 amplitude was significantly higher in SD2 than in controls. In children with absent MMN, P1, N1, and P2 latencies were significantly prolonged compared with controls, while N2 amplitude was significantly higher in children with present MMN than in those with absent MMN and controls. Conclusion MMN and CAEPs provide complementary information about auditory cortical processing in pediatric CI users. However, their relationship with speech perception should be interpreted cautiously, and electrophysiological measures should complement rather than replace behavioral assessment.