Early tone perception ability in Mandarin-speaking children with simultaneous bilateral cochlear implants 24 months post-operatively

Objective Simultaneous bilateral cochlear implantation has been shown to provide long-term benefits in children suffering from severe-to-profound hearing loss. However, very little research has been conducted on long-term benefits in Mandarin-speaking children. We aimed to (1) evaluate tone perception with simultaneous bilateral cochlear implants (CIs) compared to unilateral CIs; and (2) evaluate early auditory and speech skills. Methods The longitudinal study was comprised of 20 participants, 10 with unilateral and 10 with simultaneous bilateral CIs. Participants received a CI at a mean age of 1.3 (SD ± 0.2) years. The Mandarin Early Speech Perception test, auditory thresholds, and influence of environmental factors were measured pre-operatively and after 24 months. Categories of Auditory Performance (CAP), Speech Intelligibility Rating (SIR), and LittlEARS Auditory Questionnaire (LEAQ) were measured pre-operatively and after 6, 12, and 24 months. Results After 24 months of device use, tone perception scores tended to be higher in the bilateral CI group than in the unilateral group, although the difference did not reach statistical significance ( p = 0.058). Over the 24-month follow-up period, CAP, SIR, and LEAQ scores showed significant improvements in both groups (all p < 0.05). Conclusions Tone perception and early auditory and speech skills in Mandarin-speaking children were better with simultaneous bilateral CI implantation compared to unilateral after 24 months of use.