Children with Specific Language Impairment (SLI) often present with difficulties in learning new words compared to age-matched children with typical language development. These difficulties may affect the acquisition, storage, or retrieval of new words. Word-learning deficits impact on children’s vocabulary development and impede their language and literacy development. Findings from a wide range of studies investigating word-learning in children with SLI demonstrated that semantic and phonological knowledge are crucial to the word-learning process. However, intervention studies designed to improve the word-learning abilities in children with SLI are sparse. The experiments described in this thesis addressed this need to understand the effects of interventions on word-learning abilities. Further, the thesis describes the first investigation of word-learning abilities of New Zealand school-aged children with SLI. Specifically, the following three broad questions are asked: 1. What are the word-learning skills of New Zealand school-aged children with SLI compared to children with typical language development and which underlying language skills influence word-learning? 2. What are the immediate and longer term effects of phonological awareness and semantic intervention on word-learning and language skills in children with SLI? 3. What are the error patterns of children with SLI compared to children with typical language development when learning to produce new words and do these patterns change following phonological awareness and semantic intervention? The first experiment compared the word-learning abilities of 19 school-aged children with SLI (aged 6;2 to 8;3) to age-matched children with typical language development and revealed that children with SLI presented with significant difficulties to produce and to comprehend new words. After repeated exposure, children with SLI caught up to the performances of children with typical language development in learning to comprehend new words, but not on production of new words. Correlation analyses demonstrated that there were no correlations between the word-learning skills and other language measures for children with SLI, whereas the word-learning abilities of children with typical language development were correlated to their phonological awareness, semantic, and general language skills. In the second experiment, it was investigated whether there were also qualitative differences during word-learning between children with and without SLI additionally to the quantitative differences as revealed in the first experiment. Children’s erroneous responses during the word-learning tasks were categorised into phonological, semantic, substitution or random errors. A comparison of the children’s error patterns revealed that children with SLI presented with a different error pattern and made significantly more random errors than children with typical language development. However, after repeated exposure, children with SLI demonstrated a similar error pattern as children without SLI. Furthermore, it was examined whether a specific combination of phonological and semantic cues facilitated children’s learning of new words or whether there were word-specific features that facilitated children’s word-learning. No facilitative word-specific features could be identified. Analysis revealed that there were no significant effects of cueing on learning new words, but specific patterns could be derived for children with SLI. Children with SLI learned to comprehend more words that were presented with two semantic cues or one phonological and one semantic cue and learned to produce more words that were presented with two phonological cues. In the third experiment, the effectiveness of a combined phonological awareness and semantic intervention to advance children’s word-learning abilities was examined. Nineteen children with SLI (same participants as in experiment 1) participated in this intervention study that implemented an alternating treatment group design with random assignment of the participants. Children in group A received phonological awareness intervention followed by semantic intervention, whereas children in group B received the same interventions in the reverse order. Children’s word-learning abilities were assessed at pre-test, prior to the intervention, at mid-test after intervention phase 1, and at post-test, immediately following the completion of the second intervention phase. Each intervention itself was effective in significantly improving children’s fast mapping skills, however, gains in children’s word-learning abilities were only found for children in group A for production of new words. Extending the findings of the intervention effectiveness of phonological awareness and semantic intervention on word-learning as reported in experiment 3, it was investigated in experiment 4, whether the implemented intervention additionally influenced the error patterns of children with SLI. The erroneous responses of children with SLI on all word-learning probes at pre-, mid-, and post-test were categorised into the same error groups as described in the second experiment (semantic, phonological, substitution, and random errors). The error analyses revealed that children’s error profiles changed during the course of intervention and treatment specific effects on children’s erroneous responses were found. Post-intervention, children who received phonological awareness followed by semantic intervention displayed the same error patterns as children with typical language development, whereas children who received the same interventions in the reverse order maintained the same error pattern as displayed at pre-test. The final experiment examined the longer-term effects of the combined phonological awareness and semantic intervention reported in experiment 3 on the language and literacy development of children with SLI. Eighteen of the 19 children with SLI, who received the intervention reported in experiment 3, were available for re-assessment 6 months after the completion of the intervention. The children (aged 7;1 to 9;2 years) were re-assessed on a range of standardised and experimental measures. Data analysis revealed that 6 months post-intervention, all children were able to maintain their gains in phonological awareness, semantic, and decoding skills as displayed immediately after the intervention. Children’s general language and reading skills significantly improved following the intervention; however, children who received phonological awareness intervention followed by semantic intervention displayed significantly better reading outcomes than the children who received the same interventions in the reverse order. This thesis revealed that a combination of phonological awareness and semantic intervention can enhance the word-learning abilities of children with SLI. The combined intervention approach was also effective in additionally improving children’s general language skills and the reading of single non-words and real words, as well as connected text. The immediate and longer-term intervention effects provide evidence that advancing the semantic and phonological awareness skills is an effective intervention approach to support children with SLI in their word-learning and to furthermore promote their language and literacy development. However, the order of the implemented interventions played a significant role: Children in the current study profited most when they received phonological awareness intervention first, followed by semantic intervention.

Phonological awareness is known to be associated with reading disorder. Intervention for specific reading disorder that focuses on training to improve phonological processing abilities has been found an effective means of addressing reading difficulties experienced by children. However, little is known as to what happens to other neurocognitive abilities associated with the process of reading but that are not causally linked to it. Some of these cognitions include attention, executive functions and verbal and visual memory. A series of three studies explored the relation between neuropsychological skills and phonological abilities in children with specific reading disorder. The first step in the studies involved establishing deficits in associated cognitive abilities in children with specific reading disorder. Children attending the Literacy Clinic, Department of Communication Disorders, University of Canterbury, Christchurch, New Zealand, are screened for the presence of specific reading disorder. They are routinely assessed on reading and phonological processing measures before an intervention programme is initiated. Four such children who were assessed and identified as having specific reading disorder without speech language difficulties were chosen for the study. These children, who ranged in age from 7 to 15 years, referred to as the RD group, were assessed during the week before the onset of the intervention for the neuropsychological functions of attention, executive functions, verbal and visual learning, and memory. After the assessment (termed pre-intervention assessment), they were provided with phonological processing intervention. The intervention programme was carried out by trained speech-language therapists and lasted for 10 weeks. Two sessions a week were conducted, giving a total of 20 sessions. The week after completion of the intervention, the children were assessed once again on the same neuropsychological, reading and phonological awareness tests used before the intervention (termed post-intervention assessment). The results of the pre-intervention assessment were compared with the assessment of a group of typically developing group of children without reading disorder (N = 4; age range 8 to 10 years; referred to as the NRD group). Results indicated that, at pre-intervention assessment, the specific reading disorder (RD) group had deficits in verbal fluency and inhibitory control whereas the typically developing (NRD) group did not. The RD group also differed significantly from the NRD group in reading accuracy and comprehension. After the intervention, the RD group was assessed on reading, phonological processing, and neuropsychological tests. The group showed an improvement in reading accuracy and phonological processing. Of all the neuropsychological functions, only set shifting and visuo-spatial working memory scores showed a significant change in response to intervention. Deficits in executive functions and reading comprehension difficulties persisted. It was hypothesised that the RD group improved in reading accuracy in response to the phonological awareness intervention. However, the persistent reading comprehension difficulties were hypothesised as attributable to the presence of the executive function deficits noticed in the RD group. The exploratory study helped identify the presence of neuropsychological deficits in children with specific reading disorder in addition to their reading and phonological deficits. The study also established that phonological awareness intervention brought about a change in some neuropsychological function while other deficits persisted. The phonological awareness intervention used in the first study was developed for children in New Zealand. The second study hypothesised that, if effective, this intervention would help address reading deficits found in other populations. Children from a culture outside New Zealand accordingly the same intervention as the New Zealand children received in the first study. Children in Bangalore, India, 10 to 12 year of age and under-performing in their class, were screened for the presence of specific reading disorder. From this screening, 20 children with specific reading disorder (the RD group), with average to above average intelligence and without co-morbid psychiatric conditions were chosen to participate. Twenty children were randomly allotted to one of two treatment conditions. The first group of 10 children (the PA group) received phonological awareness intervention. The second group of 10 children (the NP group) received neuropsychological intervention. All 20 children were assessed on reading, phonological awareness tests and neuropsychological tests before and after intervention. Phonological measures included, Queensland University Inventory of Literacy (QUIL, ) Sthal and Murray, Phonological awareness probes of tracking speech sounds and non-word reading tests. Neuropsychological measures included Controlled Word Association test (COWA), Digit Span, Spatial Span, Stroop Colour-Word Test Coulor trails (A & B), Ray Auditory verbal learning test, Rey Osterriech Complex figure test and block design. The scores from the pre-intervention assessment were compared to the assessment data for 20 typically developing, non-reading-disabled children (referred to as the control group). The control group was assessed once on neuropsychological tests and reading and phonological awareness measures (QUIL only). The results indicated that the 20 children with reading disorder (the RD group) differed significantly from the control group on reading abilities. In addition, the two groups differed significantly on neuropsychological measures of attention (Colour Trail, Form A), set-shifting (Colour Trail, Form B), word reading and interference control (Stroop Colour-Word Test) and phonological awareness measures of non-word reading, syllable identification, visual rhyme, spoonerism, phoneme detection and phoneme deletion. After intervention, the RD group was again assessed on reading, phonological awareness and neuropsychological measures. Both the intervention groups (PA and NP) showed improvements on reading. Both groups also made significant gains on neuropsychological measures and phonological awareness measures. The PA group showed significant changes in verbal fluency, visual scanning and attention (Colour Trails, Form A), word reading (Stroop Colour-Word Test, verbal memory (Auditory Verbal Learning Test), immediate visual memory (Complex Figure Test) and visuo-construction abilities (Block Design Test). Phonological measures that showed significant increase in response to intervention in this group included non-word reading, phoneme detection, phoneme segmentation, phoneme deletion and tracking of syllable sound changes via use of coloured blocks and letter tiles. The NP group showed significant change in neuropsychological functions such as verbal fluency, word reading and interference control (Stroop Colour-Word Test), verbal learning (Auditory Verbal Learning Test), immediate visual memory (Complex Figure Test) and visuo-construction ability (Block Design Test). The NP group also improved significantly on phonological awareness measures such as syllable identification, spoken and visual rhyme, spoonerism, phoneme detection, phoneme deletion and tracking of syllable sound changes via use of coloured blocks. This second study established that the two interventions helped improve reading abilities equally. However, the interventions differentially affected neuropsychological and phonological awareness functioning in the participants. The third study explored the changes seen in the second study’s two treatment groups (Group PA and Group NP) three months after the conclusion of the intervention programme. During the three-month period between the post-intervention assessment and the follow-up assessment, all 20 children attended regular school. They received no special help or input for their reading and spelling difficulties during this period. The follow-up assessment consisted of the same tests of reading and neuropsychological measures used at the pre- and post-intervention assessments. The results showed that the groups had maintained the gains evident at the time of the post-intervention assessment on reading measures. The PA group’s performance on the neuropsychological measures and phonological measures showed significant changes in digit span and interference control. In addition, a significant increase from the pre-intervention measures, not observed at the post-treatment assessment, was observed for set-shifting, verbal learning and memory and now-word reading. Visuo-spatial working memory showed a trend towards significance for the NP group on the follow-up assessment. Most other neuropsychological functions did not differ significantly from those evident at the time of the post-intervention assessment. The NP group, like the PA group, showed a significant increase between pre-assessment and follow-up assessment on non-word reading, visual scanning, verbal learning and visual perception. The increase noticed in these measures at the time of the post-treatment assessment, however, was not significant. Comparisons between the PA and NP group at follow-up revealed that the PA group’s performance was significantly better than the NP group’s on digit backward and interference control, while the NP group performance was significantly better than the PA group’s on verbal fluency. The two groups were comparable on all other neuropsychological, phonological awareness and reading measures. The improvements noticed in both groups immediately after the intervention and then three months after intervention were hypothesised to have occurred because the interventions addressed reading along with other cognitive abilities (e.g., executive functions, attention, verbal learning and memory, visual learning and memory) addressed in the study. The improvements noticed in both groups after three months after intervention was hypothesised to be the outcome of improvements in the neuropsychological functions. The series of three studies conducted as part of this research work has helped identify neuropsychological deficits in children with reading disorder that persisted after phonological awareness intervention. The provision of two different interventions to children with reading difficulties showed that these had positive outcomes not only for reading and phonological awareness but also for neuropsychological functioning. The most important conclusion drawn from the findings of the three studies that form this doctoral research is that intervention for reading disorder is most likely to be effective when it addresses the reading and other associated cognitive skills that underlie the reading process. The two interventions used in the study had a similar effect on reading. Both helped the participating children improve their reading scores and both helped maintain those improvements over time. It is hypothesised that the improvement observed was probably sustained over time because both interventions could have addressed the associated deficits (in addition to reading difficulties) known to occur in children with reading disorder. The efficacy of the phonological awareness intervention documented in the studies is strengthened by the finding that it was effective in treating reading disorders in children from different cultural and educational settings (New Zealand and India).

Sound-field amplification systems (SFA) have proven effective in overcoming classroom listening difficulties associated with noise, distance and reverberation. However, whether improving the classroom listening environment is sufficient to enhance young children’s learning in areas critical to early reading acquisition, such as awareness of the sound structure of spoken words (phonological awareness: PA), is unclear. This study aimed to examine the effectiveness of an enhanced listening environment combined with PA intervention which aimed to specifically increase children’s PA compared to an enhanced listening environment alone. Participants were 38 children aged 5-6 years from two classes at a low-decile primary school. All children were hearing screened at baseline, pre- and post-intervention. PA, letter-sound knowledge, real and non-word decoding were measured three times over 10 weeks (Term 1) prior to SFA installation in both classrooms, as well as pre- and post-intervention. In Term 2, children in class 1 were randomly assigned to receive SFA and an eight-week class-based teacher-administered PA programme. Class 2 received SFA only. A significant learning effect for all children occurred during the first phase of the monitoring period. Yet, a plateau was reached for most children between assessment times two and three prior to intervention. Following intervention, class 1 demonstrated a significant difference compared to class 2 in one PA assessment. Other measures failed to show any differences between classes. Visual data analyses revealed particular (non-significant) improvements for poor readers in class 1. These children outperformed poor readers in class 2 on all measures. Teacher questionnaires indicated that children’s listening skills improved with SFA. The significant difference observed in one measure of PA between classes demonstrated that the combination of enhanced classroom acoustic environment and PA intervention actively improved PA development. The results of this study have implications for: (a) facilitating attention to sound structure, (b) optimal intervention for early PA development, (c) early reading acquisition in New Zealand classrooms, and, (d) the use of typical models of professional teacher development.

Early reading skills are the foundation of children’s academic success (Lonigan et al., 1999). Unfortunately reading difficulties are highly prevalent in school children (National Center for Education Statistics, 2007) and can have significant and long-lasting negative impacts on academic, social, and vocational achievement (Sylva & Hurry, 1996). A link between difficulties in reading and behaviour problems has also been widely noted in the literature. Few studies have, however, examined the impact of reading interventions on both reading and behaviour skills for children, particularly for children with mild to moderate behavioural issues. This is an important area of research in determining the effects of literacy intervention, and disentangling the complex relationship between reading and behavioural difficulties. Accordingly, the current study aimed to monitor the effectiveness of a specialist reading intervention on children's literacy skills and behaviour. The research employed a multiple case study design, and was separated into three phases (a pre-testing phase, intervention phase, and post-test phase). Participants consisted of 11 students from two Christchurch Primary schools who had difficulties in reading, as well as five teachers, two literacy teachers, and one teacher aide. Four participants, who exhibited more severe behaviour (as identified by their teacher on the Strengths and Difficulties Questionnaire) at pre-test, were selected as case study participants. Case study participants’ literacy teachers provided additional information regarding the students’ behaviour. All participants completed pre- and post-literacy (reading and spelling) and phonological awareness assessments and students were observed in the classroom setting. Teachers also completed surveys in regards to the students’ classroom behaviour over the course of the intervention. The Agility with Sound intervention primarily targets phonological awareness and application of phonological decoding strategies in reading. The intervention also focuses on vocabulary development and reading comprehension. At School 1, participants attended four, 1 hour sessions each week as a small-group. At School 2, participants attended three sessions each week for 30 minutes. Differences in intervention scheduling and content across the two schools restricted the research design that could be employed to establish the effects of the specialist teaching. Results showed that the majority of participants showed an increase in raw score for the Letter-word Identification (n=11), Word Attack (n=7), and Helen Arkell Spelling Test (n=9), indicating that the research intervention had a significant, positive impact on children’s word identification, decoding, and spelling skills. No significant differences were found between pre- and post-test measures of behaviour, however, qualitative data from teachers indicated that for four participants, some change in classroom behaviour was evident following intervention. Findings from case study students indicated that Participant 9 who had the most reported difficulties during literacy sessions (as reported by her literacy teacher), demonstrated the least progress in literacy; demonstrating decreases in spelling and reading raw scores following the intervention period. The remaining case study participants all demonstrated increases in reading, spelling, and phonological awareness (with the exception of Participant 3 who showed no change in phonological awareness). All participants (with the exception of Participant 11 whose teacher-report of classroom behaviour remained the same from pre- to post-test) also demonstrated decreased raw scores in observation of problem classroom behaviours and teacher-reports of problem classroom behaviours over the course of the intervention period. A correlation analysis did not show a significant association between change in literacy and change in classroom behaviour following the intervention period. The current research supports the use of Agility with Sound for enhancing school children’s literacy skills, and highlights the importance of combining literacy and behavioural intervention to enhance both literacy and classroom behaviour skills for children with co-morbid difficulties.

This study examined English and French literacy skills among language minority children in French immersion. Forty children with a first language other than English (non-English L1) and forty-one native English-speaking (EL1) children were examined on phonological awareness, rapid automatized naming, word reading, and English vocabulary at the beginning and end of Grade 1. They were also examined on phonological awareness, word reading, and French vocabulary at the end of the year. Non-English L1children experienced greater growth in English expressive vocabulary, and similar growth in English receptive vocabulary, to that of EL1 children. There was a cross-language transfer of phonological awareness and word reading from English to French, and cross-language relationship between English receptive vocabulary and French receptive vocabulary for both groups. Non-English L1 children do not lag behind in early English skills, even when their English exposure is limited in a French immersion setting.

This study examined English and French literacy skills among language minority children in French immersion. Forty children with a first language other than English (non-English L1) and forty-one native English-speaking (EL1) children were examined on phonological awareness, rapid automatized naming, word reading, and English vocabulary at the beginning and end of Grade 1. They were also examined on phonological awareness, word reading, and French vocabulary at the end of the year. Non-English L1children experienced greater growth in English expressive vocabulary, and similar growth in English receptive vocabulary, to that of EL1 children. There was a cross-language transfer of phonological awareness and word reading from English to French, and cross-language relationship between English receptive vocabulary and French receptive vocabulary for both groups. Non-English L1 children do not lag behind in early English skills, even when their English exposure is limited in a French immersion setting.

The purpose of this study was to examine the role of music perception in predicting phonological awareness in five- and six-year-old children. This study was based on the hypothesis that music perception and phonological awareness appear to have parallel auditory perceptual mechanisms. Previous research investigating the relationship between these constructs—music perception and phonological awareness—has been promising, but inconclusive. Phonological awareness is an important component of early literacy which many children struggle to acquire. If the constructs are shown to be related, music-based interventions may then be developed to promote phonological awareness, thus enhancing early literacy. Music perception, phonological awareness, and visual-spatial skills of 119 five- and six-year-old children were tested. The researcher administered the Children’s Music Aptitude Test (Stevens, 1987) in order to assess perception of pitch, rhythm, and melody. Subsequently, the Comprehensive Test of Phonological Processing (Wagner, Torgesen, & Rashotte, 1999) was administered in order to measure phonological awareness skills, including blending, elision, and sound matching. The Visual Spatial Relations subtest of the Woodcock Johnson III (Woodcock, McGrew, & Mather, 2001) was later used to assess visual spatial skills. Structural equation modeling (SEM) allowed the researcher to model relationships between the latent variables to investigate the contribution of music perception, visual-spatial skills, and age to phonological awareness. Results supported the hypothesis that music perception, visual spatial skills, and age predict phonological awareness. Additionally, music perception made a statistically significant contribution to phonological awareness, when controlling for visual spatial skills and age. Specifically, music perception predicted a larger amount of standardized unit change in phonological awareness than did the other predictors in the theory. Thus, music perception appears to have a stronger relationship with phonological awareness than age or visual spatial skills. Further, results showed that a model without music perception as a predictor of phonological awareness was not supported. These findings confirm that music perception plays a unique role in predicting phonological awareness, above and beyond the contribution made by visual spatial skills and age. This study’s results could be used in support of the development of music-based interventions for promoting phonological awareness in five- and six-year-old children.

The development of reading competency is one of the most significant pedagogical achievements during the first few years of schooling. Although most children learn to read successfully when exposed to reading instruction, up to 18% of children experience significant reading difficulty (Shaywitz, 1998). As a group, young children with speech impairment are at risk of reading impairment, with approximately 50% of these children demonstrating poor acquisition of early reading skills (Nathan, Stackhouse, Goulandris, & Snowling, 2004; Larivee & Catts, 1999). A number of variables contribute to reading outcomes for children with speech impairment including co-occurring language impairment, the nature and severity of their speech impairment as well as social and cultural influences. An area of research that has received increasing attention is understanding how access to the underlying sound structure or phonological representations of spoken words stored in long-term memory account for reading difficulties observed in children (Elbro, 1996; Fowler, 1991). Researchers have hypothesised that children with speech impairment may be at increased risk of reading disability due to deficits at the level of phonological representations (Bird, Bishop, & Freeman, 1995). Phonological representation deficits can manifest in poor performance on tasks that require children to think about the sound structure of words. Knowledge about the phonological components of words is commonly referred to as phonological awareness. Identifying and manipulating phonemes within words are examples of phonological awareness skills. Some children with speech impairment perform poorly on phonological awareness measures compared to children without speech difficulties (Bird et al., 1995; Carroll & Snowling, 2004; Rvachew, Ohberg, Grawburg, & Heyding, 2003). As performance on phonological awareness tasks is a strong predictor of early reading ability (Hogan, Catts, & Little, 2005), there is an important need to determine if children with speech impairment who demonstrate poor phonological awareness, have deficits at the level of phonological representations. This thesis reports a series of studies that investigated the relationship between phonological representations, phonological awareness, and word decoding ability in children with moderate to severe speech impairment. A child with complex communication needs (CCN) who used Augmentative and Alternative Communication (AAC) was also examined to determine how the absence of effective articulation skills influences the development of phonological representations. The study employed a longitudinal design to compare the performance of nine children (aged 3:09-5:03 at initial assessment) with moderate to severe speech impairment and 17 children with typical speech development on novel assessment measures designed to determine characteristics of children's phonological representations. The tasks required children to judge the accuracy of spoken multisyllable words and newly learned nonwords. The relationships between performance on these tasks and measures of speech, phonological awareness and early print decoding were also examined. Four assessment trials were implemented at six-monthly intervals over an 18-month period. The first assessment trial was administered approximately 6 to12 months before children commenced school. The fourth trial was administered after children had completed 6 to 12 months of formal education. The child with CCN completed three assessment trials over a period of 16 months. Data analyses revealed that the children with speech impairment had significantly greater difficulty (p<0.01) judging mispronounced multisyllable words compared to their peers with typical speech development. As a group, children with speech impairment also demonstrated inferior performance on the judgment of mispronounced forms of newly learned nonwords (p<0.05). No group differences were observed on the judgment of correctly pronounced real and nonword stimuli. Significant group differences on speech production and phoneme segmentation tasks were identified at each assessment trial. Moderate to high correlations (i.e., r = 0.40 to 0.70) were also observed between performance on the phonological representation tasks and performance on phonological awareness and speech production measures at each trial across the study. Although no significant group differences were observed on the nonword decoding task, 4 of the 9 children with speech impairment could not decode any letters in nonwords (compared to only 1 child without speech impairment) at the final assessment trial when children were 6-years-old. Two children with speech impairment showed superior nonword decoding ability at trial 3 and 4. The within-group variability observed on the nonword decoding task highlighted the heterogeneity of children with speech impairment. The performances of four children with speech impairment with differing types of speech error patterns were analysed to investigate the role of phonological representations in their speech and phonological awareness development. The child with delayed speech development and excellent phonological awareness at trial 1, demonstrated superior phonological awareness and word decoding skills at age 6 years, although his performance on phonological representation tasks was inconsistent across trials. In contrast, a child with delayed development and poor early phonological awareness demonstrated weak performance on phonological representation, phonological awareness, and decoding at each successive assessment trial. The child with a high percentage of inconsistent speech error patterns generally demonstrated poor performance on phonological representation, phonological awareness and decoding measures at each of the 4 assessment trials. The child with consistent and unusual speech error patterns showed increasingly stronger performance on the phonological representation tasks and average performance on phonological awareness but limited word decoding ability at age 6. The 11-year-old girl with CCN, whose speech attempts were limited and unintelligible, demonstrated below average performance on phonological representation tasks, suggesting that an absence of articulatory feedback may negatively influence the development of well-specified phonological representations. This thesis provides evidence for the use of receptive tasks to identify differences in the phonological representations of children with and without speech impairment. The findings also provide support for the link between the representation of phonological information in long-term memory and children's speech production accuracy, phonological awareness and print decoding ability. The variable performance of some children with speech impairment and the child with cerebral palsy demonstrate the need to consider individual characteristics to develop an understanding of how children store and access speech sound information to assist their acquisition of early reading skills.

Children with Specific Language Impairment (SLI) often present with difficulties in learning new words compared to age-matched children with typical language development. These difficulties may affect the acquisition, storage, or retrieval of new words. Word-learning deficits impact on children’s vocabulary development and impede their language and literacy development. Findings from a wide range of studies investigating word-learning in children with SLI demonstrated that semantic and phonological knowledge are crucial to the word-learning process. However, intervention studies designed to improve the word-learning abilities in children with SLI are sparse. The experiments described in this thesis addressed this need to understand the effects of interventions on word-learning abilities. Further, the thesis describes the first investigation of word-learning abilities of New Zealand school-aged children with SLI. Specifically, the following three broad questions are asked: 1. What are the word-learning skills of New Zealand school-aged children with SLI compared to children with typical language development and which underlying language skills influence word-learning? 2. What are the immediate and longer term effects of phonological awareness and semantic intervention on word-learning and language skills in children with SLI? 3. What are the error patterns of children with SLI compared to children with typical language development when learning to produce new words and do these patterns change following phonological awareness and semantic intervention? The first experiment compared the word-learning abilities of 19 school-aged children with SLI (aged 6;2 to 8;3) to age-matched children with typical language development and revealed that children with SLI presented with significant difficulties to produce and to comprehend new words. After repeated exposure, children with SLI caught up to the performances of children with typical language development in learning to comprehend new words, but not on production of new words. Correlation analyses demonstrated that there were no correlations between the word-learning skills and other language measures for children with SLI, whereas the word-learning abilities of children with typical language development were correlated to their phonological awareness, semantic, and general language skills. In the second experiment, it was investigated whether there were also qualitative differences during word-learning between children with and without SLI additionally to the quantitative differences as revealed in the first experiment. Children’s erroneous responses during the word-learning tasks were categorised into phonological, semantic, substitution or random errors. A comparison of the children’s error patterns revealed that children with SLI presented with a different error pattern and made significantly more random errors than children with typical language development. However, after repeated exposure, children with SLI demonstrated a similar error pattern as children without SLI. Furthermore, it was examined whether a specific combination of phonological and semantic cues facilitated children’s learning of new words or whether there were word-specific features that facilitated children’s word-learning. No facilitative word-specific features could be identified. Analysis revealed that there were no significant effects of cueing on learning new words, but specific patterns could be derived for children with SLI. Children with SLI learned to comprehend more words that were presented with two semantic cues or one phonological and one semantic cue and learned to produce more words that were presented with two phonological cues. In the third experiment, the effectiveness of a combined phonological awareness and semantic intervention to advance children’s word-learning abilities was examined. Nineteen children with SLI (same participants as in experiment 1) participated in this intervention study that implemented an alternating treatment group design with random assignment of the participants. Children in group A received phonological awareness intervention followed by semantic intervention, whereas children in group B received the same interventions in the reverse order. Children’s word-learning abilities were assessed at pre-test, prior to the intervention, at mid-test after intervention phase 1, and at post-test, immediately following the completion of the second intervention phase. Each intervention itself was effective in significantly improving children’s fast mapping skills, however, gains in children’s word-learning abilities were only found for children in group A for production of new words. Extending the findings of the intervention effectiveness of phonological awareness and semantic intervention on word-learning as reported in experiment 3, it was investigated in experiment 4, whether the implemented intervention additionally influenced the error patterns of children with SLI. The erroneous responses of children with SLI on all word-learning probes at pre-, mid-, and post-test were categorised into the same error groups as described in the second experiment (semantic, phonological, substitution, and random errors). The error analyses revealed that children’s error profiles changed during the course of intervention and treatment specific effects on children’s erroneous responses were found. Post-intervention, children who received phonological awareness followed by semantic intervention displayed the same error patterns as children with typical language development, whereas children who received the same interventions in the reverse order maintained the same error pattern as displayed at pre-test. The final experiment examined the longer-term effects of the combined phonological awareness and semantic intervention reported in experiment 3 on the language and literacy development of children with SLI. Eighteen of the 19 children with SLI, who received the intervention reported in experiment 3, were available for re-assessment 6 months after the completion of the intervention. The children (aged 7;1 to 9;2 years) were re-assessed on a range of standardised and experimental measures. Data analysis revealed that 6 months post-intervention, all children were able to maintain their gains in phonological awareness, semantic, and decoding skills as displayed immediately after the intervention. Children’s general language and reading skills significantly improved following the intervention; however, children who received phonological awareness intervention followed by semantic intervention displayed significantly better reading outcomes than the children who received the same interventions in the reverse order. This thesis revealed that a combination of phonological awareness and semantic intervention can enhance the word-learning abilities of children with SLI. The combined intervention approach was also effective in additionally improving children’s general language skills and the reading of single non-words and real words, as well as connected text. The immediate and longer-term intervention effects provide evidence that advancing the semantic and phonological awareness skills is an effective intervention approach to support children with SLI in their word-learning and to furthermore promote their language and literacy development. However, the order of the implemented interventions played a significant role: Children in the current study profited most when they received phonological awareness intervention first, followed by semantic intervention.

abstract: A substantial amount of research demonstrates that preschoolers' phonological awareness skills are a robust predictor of children's later decoding ability. Several investigators examined performance of children with speech sound impairment (SSI), defined as inaccurate production of speech sounds in the absence of any etiology or communication impairment, on phonological awareness tasks. Investigators found that children with SSI scored below their typically developing peers (TD) on phonological awareness tasks. In contrast, others found no differences between groups. It seems likely that differences in findings regarding phonological awareness skills among children with SSI is the fact that there is considerable heterogeneity among children with SSI (i.e., speech errors can either be a phonological or articulation). Phonology is one component of a child's language system and a phonological impairment (SSI-PI) is evident when patterns of deviations of speech sounds are exhibited in a language system. Children with an articulation impairment (SSI-AI) produce speech sound errors that are affected by the movements of the articulators, not sound patterns. The purpose of the study was to examine whether or not children with SSI-PI are at greater risk for acquiring phonological awareness skills than children with SSI-AI. Furthermore, the phonological awareness skills of children with SSI-PI and SSI-AI were compared to those of their typical peers. In addition, the role of executive function as well as the influence of phonological working memory on phonological awareness task performance was examined. Findings indicate that the SSI-PI group performed more poorly on an assessment of phonological awareness skills than the SSI-AI and TD groups. The SSI-PI group performed significantly more poorly on tasks of executive function and phonological working memory than the TD group. The results of this study support the hypothesis that children with SSI-PI may be more vulnerable to difficulties in reading than children with SSI-AI and children with TD. / Dissertation/Thesis / Doctoral Dissertation Speech and Hearing Science 2015