A Study on the Phonetic Inventory Development of Children with Cochlear Implants for 5 Years after Implantation

This paper investigates longitudinal phonetic inventories of vowels and consonants of Korean-speaking children with cochlear implants (CIs). They are based on speech data of 7 children with CI over 5 years PI to examine the entire speech production development. Phones produced at least twice by more than 50% children in spontaneous and imitation speech from 6 months to 5 years post-implantation (PI) are compiled in the inventories. The results show and differences and similarities between children with CI and with normal hearing (NH). The vowel and consonant inventories at 6 months PI are larger than those of NH children at 1 year of age whose hearing experience is longer, including liquid [ɾ] and fricative [s]. It can be attributed to biological maturation of CI children. As in children with NH, there is an explosive increase in phonetic inventories during a year after 1-year of robust hearing experience and the inventories are almost complete after 3 years of PI. Phonetic inventories at each time are expected to be references to assess the developmental appropriateness in speech production and guides to direct habilitation goals.