[Effect of cochlear implantation on speech recognition under different listening modes in children]

Objective:To investigate speech recognition among children with a unilateral cochlear implant（CI）, bilateral CI, and bimodal hearing and identify the benefits of binaural hearing. Methods:A total of 67 children with severe sensorineural hearing loss who received bilateral CI, bimodal hearing, and unilateral CI from 2012 to 2021 were recruited, including 23 cases with unilateral CI, 25 cases of bimodal hearing, and 19 cases of bilateral CI. The aided hearing threshold at 250-4000 Hz and speech recognition performance of two-syllable words and short sentences in quiet and noisy environments were tested, respectively. Results:There was no significant difference in the hearing threshold results of the bilateral CI group, the bimodal hearing group, and the unilateral CI group by ANOVA（P>0.05）. According to the paired t-test within the group, the speech recognition of disyllabic words and short sentences in quiet and noisy environments were significantly different among the three groups（P<0.05）. There was no significant difference in the speech recognition rates of disyllabic words and short sentences among the three groups in a quiet environment（P>0.05）, but there was a statistically significant difference in a noisy environment（P<0.05）. Additional multiple linear regression analysis showed no significant difference in the recognition rates of disyllabic words and short sentences between the bimodal group and the bilateral CI group in quiet and noisy environments（β=-0.567, P>0.05; β=-0.643, P>0.05）. There was a statistically significant difference in speech recognition of disyllabic words and short sentences between the bimodal group and the unilateral CI group in the noise environment（β=-0.124, P<0.05）, but the difference was not statistically significant in a quiet environment（β=-0.671, P>0.05）; there was a statistically significant difference in the recognition rate of disyllabic words and short sentences between the bilateral CI group and the unilateral CI group in the noise environment（β=-0.226, P<0.05）, but the difference was not statistically significant in a quiet environment（β=-0.341, P>0.05）. Conclusion:Clinicians and guardians are encouraged to provide the most comprehensive audiological evaluation for children with hearing loss. Bilateral CI and bimodal hearing have demonstrated enormous advantages over unilateral CI regarding speech recognition in noise. Bimodal hearing deems a strong recommendation if the contralateral ear has sufficient speech recognition capability. Bilateral CI should be warranted if hearing aids deemed to be ineffective.