Speech production and speech production accuracy in young children: hearing and hearing impaired children with a cochlear implant
3 May 2017
UAntwerp, Stadscampus, Willem Ellschotzaal - Prinsstaat 13b - 2000 Antwerpen (route: UAntwerpen, Stadscampus
3:00 PM - 5:30 PM
Prof Steven Gillis
PhD defence Jolien Faes - Faculty of Arts
This dissertation considers the longitudinal phonological development of children with cochlear implants (CI) in comparison to that of normally hearing peers. The spontaneous speech productions of children with CI are investigated both at the word level for accuracy and variability and at the segmental level with respect to consonant clusters and fricatives. Analyses showed that children with CI’s speech production improves with age.
Words and segments become less variable and more accurate. Slightly better outcomes are found in children that receive their implant at an earlier age. In comparison to normally hearing peers, children with CI’s word productions are less accurate and more variable. Moreover, the characteristics of the target word (syllable length, complexity and frequency in child-direct speech) affect children with CI’s word productions to a different extent.
Target words that have more syllables and are more complex are less accurate and more variable in both groups of children, but the effect is more pronounced in children with CI. In contrast, target words that are more frequent in child-directed speech are more accurate, but this effect is less pronounced in children with CI. At the segmental level, children with CI’s consonant cluster production is delayed as compared to that of normally hearing age-mates.
However, for all of these measures, a catch up is found: children with CI reach similar levels of phonological development as their normally hearing age-mates by age five for accuracy and variability at the word level and for consonant cluster production. With respect to fricatives, results showed that children with CI are delayed in their production when compared to normally hearing age-mates, but not when compared to normally hearing children with an equal lexicon size. In other words, phonological development and lexical development are commensurate in children with CI, similarly to NH children. Next to phonological development, sentence length and inflectional richness were investigated.
Results showed that normally hearing children produce longer sentences and have a higher inflectional diversity than children with CI. Similarly to the results considering phonological development, children with CI are found to catch up on their normally hearing peers: by age five for inflectional richness and by age seven for sentence length. Thus, the present dissertation showed that it is crucial to trace the long-term language development of children with CI’s spontaneous speech productions.