Speech Profile of School-age Children with Hearing Loss in Comparison to Children with Normal Hearing in New Zealand

Abstract

Aims of doctoral thesis were to: 1) describe the phonetic inventory of New Zealand English (NZE) of early school-age children with mild-to-profound HL in comparison to their peers, 2) examine vowel and consonant production accuracy of school-age children with mild-to-profound HL in comparison to their normal hearing peers and to examine, 3) identify the phonological processes that persist in the speech of school-age children with hearing loss (CWHL) in comparison to their peers, and 4) investigate how the speech-intelligibility of CWHL and children with normal hearing (CWNH) is rated by adult listeners with differing levels of familiarity with a child’s speech characteristics. Methods: Children with hearing loss (CWHL, N=25; mean age of identification=25.9) were compared with children with normal hearing (CWNH, N=30) with similar age, gender, linguistic, and socioeconomic backgrounds. Productions of English words were elicited in a picture-naming task using a list of 88 words, derived from three standardized speech tests. Parents (N=24), teachers (N=24), inexperienced listeners (N=24) and experienced listeners (N=24) rated children’s speech intelligibility on a 6-point scale. Results: The first study showed that CWHL produced fewer stops, fricatives, affricates, and liquids than CWNH. CWHL had acquired more sounds in onset than coda position. Most CWHL had similar vowel repertoires to CWNH. The second study showed that CWHL and CWNH had similar vowel production accuracy. CWHL had lower percentage of consonant correct than CWNH. Consonant production accuracy for CI users was better than for HA users. Children with moderate-to-severe HL were the least accurate in phonemic production. The third study revealed that there was distinctive differences between CWNH and CWHL in the amount of processes produced by younger and older CWHL. CWHL showed a similar trend of age of suppression to CWNH but at a slower rate. Final consonant deletion, weak syllable deletion, backing, and glottal replacement were present in the speech of HA users which would affect their overall speech intelligibility. The fourth study showed that parents, teachers, and experienced listeners rated speech intelligibility of CWHL better than inexperienced listeners. Conclusions: Some children with mild to profound hearing loss had reduced phonetic repertoires compared to their peers at early school age. Children with moderate-to-severe hearing loss who are fitted with hearing aids need comprehensive assessment and intervention services. The findings indicate that it is important for clinicians to consider phonological assessment in CWHL and the use of evidence-based speech therapy for pre-school CWHL to reduce the presence of non-developmental and non-age-appropriate developmental processes in order to enhance their speech intelligibility. Finally, it is helpful in clinical contexts to consider the perceptions of parents and other listeners who are familiar with a child’s speech, and the perceptions of less familiar listeners when evaluating the intelligibility of CWHL.