Early Vocal Development in Toddlers With Simultaneous Bilateral Cochlear Implants

Background and Objectives The purpose of this study is to investigate the vocal development in toddlers with simultaneous bilateral cochlear implants (bilateral CI group) and to compare their progress to that of chronological age-matched (CA group) and hearing agematched (HA group) toddlers who have normal hearing and typical development.Subjects and Method Thirteen toddlers who received bilateral CIs simultaneously before 18 months of age participated in this study. Twenty-six toddlers participated as the control groups (CA group and HA group). The spontaneous utterances were collected from each toddler during free play with their parents in the laboratory. A total of 2324 spontaneous utterances of 39 toddlers (13 toddlers in each of the three groups) were classified as either canonical vocalizations or noncanonical vocalizations.Results The bilateral CI group produced significantly fewer canonical vocalizations than the CA group. However, there was not a significant difference in the ratio of canonical vocalizations between the CI and the CA groups. There were no significant differences in the frequency and ratio of canonical vocalization between the CI and HA groups. In the CI group, the frequency of canonical and noncanonical vocalizations was significantly correlated with receptive and expressive language scores.Conclusion The findings of this study showed that toddlers with bilateral CIs make good advancements in vocal development compared to toddlers with normal hearing. However, toddlers with bilateral CIs seem to produce an insufficient quantity of canonical vocalizations compared to age-matched hearing toddlers. Information about vocal development following simultaneous bilateral CI helps speech therapists and parents recognize speech development before the use of intelligible speech in communication.