The effect of core vocabulary therapy on speech outcomes for a child with an auditory brainstem implant : a pilot study

Core Vocabulary Therapy (CVT) is a well-studied language-based treatment for speech sound disorders originally designed for hearing children with highly unintelligible speech (Dodd, Holm, Crosbie & McIntosh, 2010). CVT seeks to help children create consistent productions of high-frequency, functional words and to generalize these consistent productions to spontaneous speech. Recently Herman and colleagues examined the efficacy of this treatment approach with pediatric cochlear implant (CI) users, and demonstrated that CVT can enhance consistency of speech production and speech intelligibility of children with severe to profound hearing loss who were fit with a CI (Herman, Thomas, Oyebade, Bennett, & Dodd, 2015). The efficacy of CVT with CI users warrants an exploration of this treatment approach for children with auditory brainstem implants (ABIs). With this in mind, we examined the impact of a CVT treatment approach on speech sound acquisition and word production for a pediatric ABI user. Specifically, this study aimed to determine whether CVT would lead to an increase in elicited vocalizations and spontaneous vocalizations. Secondly, the effects of CVT on phonemic inventory size, syllable shape inventory size, and overall use of syllable shapes were explored. CVT was administered twice a week for five weeks using vocabulary chosen based on relevance to the participant and developmentally appropriate sound and syllable shapes. Pre-and post-speech characteristics were compared following the completion of treatment. Post-test characteristics showed an increase in both elicited and spontaneous vocalizations. Elicited vocalizations demonstrated greater linear growth than spontaneous vocalizations. Post-test data also demonstrated an increase in phonemic inventory size, as the participant added one phoneme to her inventory and demonstrated emergence of two other phonemes. Syllable shape inventory also increased, as the participant acquired two syllable shapes. Finally, overall syllable shape use increased, and the participant demonstrated use of simultaneous voicing while producing the oral posture of syllable shapes. In summary, results from this study demonstrate that CVT may lead to positive changes in speech sound acquisition and development. Based on these results, CVT merits further research as an effective approach for children with ABIs.