Crucial Music Components Needed for Speech Perception Enhancement of Pediatric Cochlear Implant Users: A Systematic Review and Meta-Analysis

Background: Although many clinicians have attempted music training for the hearing-impaired children, no specific effects have yet been reported for individual music components. This paper seeks to discover specific music components that help in improving speech perception of children with cochlear implants (CI) and to identify the effective training periods and methods needed for each component. Method: While assessing 5 electronic databases, that is, ScienceDirect, Scopus, PubMed, CINAHL, and Web of Science, 1,638 articles were found initially. After the screening and eligibility assessment stage based on the Participants, Intervention, Comparisons, Outcome, and Study Design (PICOS) inclusion criteria, 18 of 1,449 articles were chosen. Results: A total of 18 studies and 14 studies (209 participants) were analyzed using a systematic review and meta-analysis, respectively. No publication bias was detected based on an Egger's regression result even though the funnel plot was asymmetrical. The results of the meta-analysis revealed that the largest improvement was seen for rhythm perception, followed by the perception of pitch and harmony and smallest for timbre perception after the music training. The duration of training affected the rhythm, pitch, and harmony perception but not the timbre. Interestingly, musical activities, such as singing, produced the biggest effect size, implying that children with CI obtained the greatest benefits of music training by singing, followed by playing an instrument and achieved the smallest effect by only listening to musical stimuli. Significant improvement in pitch perception helped with the enhancement of prosody perception. Conclusion: Music training can improve the music perception of children with CI and enhance their speech prosody. Long training duration was shown to provide the largest training effect of the children's perception improvement. The children with CI learned rhythm and pitch better than they did with harmony and timbre. These results support the finding of past studies that with music training, both rhythm and pitch perception can be improved, and it also helps in the development of prosody perception.