Beginning to communicate after cochlear implantation: oral language development in a young child

This longitudinal case study examined the emergence of a wide range of oral language skills in a deaf child whose cochlear implant was activated at 20 months. The main purposes of this study were to determine "Hannah's" rate of spoken language development during her second to fourth year of implant experience and to estimate the efficiency of her progress by comparing her performance to that of typically developing children. Mother-child interactions were also examined to determine changes in Hannah's communication competence. Normal or above-normal rates of development were observed in the following areas: (a) decreased production of nonwords, (b) increased receptive vocabulary, (c) type-token ratio, (d) regular use of word combinations, and (e) comprehension of phrases. Below-normal rates of development were observed in the following areas: (a) speech intelligibility, (b) number of word types and tokens, and (c) mean length of utterance in morphemes. Analysis of parent-child interactions showed a large increase in responses to questions during the third year of implant use. Data from Hannah's first post-implantation year (D. J. Ertmer & J. A. Mellon, 2001) indicated that some early language milestones were attained quite rapidly (e.g., canonical vocalizations and emergence of first word combinations). In contrast, the current study revealed that progress had slowed for related, but more advanced skills (e.g., production of intelligible speech and consistent use of word combinations). These changes in rate of development suggest that any advantages for language learning due to Hannah's advanced maturity (or other unknown factors) decreased with time and increasing linguistic complexity.