Yvonne E Wren

The Influence of Bilingualism on Speech Production: A Systematic Review.

BACKGROUND Children who are bilingual and have speech sound disorder are likely to be under-referred, possibly due to confusion about typical speech acquisition in bilingual children. AIMS To investigate what is known about the impact of bilingualism on childrens acquisition of speech in English to facilitate the identification and treatment of bilingual children with speech sound disorder. METHODS & PROCEDURES A systematic review of studies from the last 50 years was conducted. Studies investigating speech acquisition in bilingual infants and children (where one language was English) were identified through searching seven electronic databases, bibliographies of relevant articles and e-mailing authors. Sixty-six studies investigating bilingual speech production met inclusion criteria, with 53 describing typically developing children and 13 describing children with speech sound disorder. The 66 studies were analysed thematically and summarized in terms of methods, key findings and underlying theories. MAIN CONTRIBUTION There was limited evidence to suggest that bilingual children develop speech at a slower rate than their monolingual peers; however, there was evidence for qualitative differences and increased variation in speech production. Nearly all studies provide evidence for transfer between the two phonological and language structures, although the amount of transfer varied between studies. There was evidence of positive and negative transfer of features from the dominant language (L1) to the second language (L2) as well as from L2 to L1. Positive transfer became more evident with increased age and length of exposure to a second language. More recently researchers have moved away from investigating whether there are one or two phonological systems and accept that there are two systems that interact. Interest has shifted to examining how phonological systems interact and to identifying factors that influence interactions. The review revealed a number of inconsistencies in the findings of studies due to differences in methodology, languages investigated and degree of language exposure. Overall, measurement issues were addressed well but most studies provided limited sample information about language experience, schooling and socio-economic status. CONCLUSIONS & IMPLICATIONS There are differences in speech sound acquisition between monolingual and bilingual children in terms of rate and patterns of error, with both positive and negative transfer occurring in bilingual children.

Common variation near ROBO2 is associated with expressive vocabulary in infancy

Twin studies suggest that expressive vocabulary at ~24 months is modestly heritable. However, the genes influencing this early linguistic phenotype are unknown. Here we conduct a genome-wide screen and follow-up study of expressive vocabulary in toddlers of European descent from up to four studies of the EArly Genetics and Lifecourse Epidemiology consortium, analysing an early (15–18 months, ‘one-word stage’, NTotal=8,889) and a later (24–30 months, ‘two-word stage’, NTotal=10,819) phase of language acquisition. For the early phase, one single-nucleotide polymorphism (rs7642482) at 3p12.3 near ROBO2, encoding a conserved axon-binding receptor, reaches the genome-wide significance level (P=1.3 × 10−8) in the combined sample. This association links language-related common genetic variation in the general population to a potential autism susceptibility locus and a linkage region for dyslexia, speech-sound disorder and reading. The contribution of common genetic influences is, although modest, supported by genome-wide complex trait analysis (meta-GCTA h215–18-months=0.13, meta-GCTA h224–30-months=0.14) and in concordance with additional twin analysis (5,733 pairs of European descent, h224-months=0.20).

A comparison between computer and tabletop delivery of phonology therapy

This paper reports on the development and evaluation of a software program aimed at assisting children with phonological impairment. An experimental approach was used whereby childrens speech output was assessed pre- and post-therapy. Children were randomly assigned to a computer, a tabletop or a no therapy group. Those children receiving the computer therapy were exposed to an experimental software program that mirrored the tabletop activities using interactive computer games. The results showed no significant difference between any of the three groups with regard to change in speech output. These results may relate to the amount and frequency of therapy given and also to the heterogeneous nature of children included in the study. There was considerable variation in individual performance across all three groups and the data were therefore analysed to look for patterns that might predict performance. Stimulability and gender were identified as possible predictors. Female children and those who were able to produce a greater number of consonant speech sounds in isolation were more likely to make progress in their speech output. Future research might use a similar methodology to compare the therapy conditions but with a more homogenous group in terms of stimulability and using a greater intensity of intervention.

Distinguishing groups of children with persistent speech disorder: Findings from a prospective population study

Abstract As part of a large-scale study of childrens development, 7390 children were assessed on a range of speech tasks. These were used to identify three groups of children with speech errors within the sample: persistent speech disorder (PSD); speech errors but below the threshold for classification as persistent speech disorder (non-PSD); and common clinical distortions only (CCD). These three groups were compared on demographic factors, performance on IQ, non-word repetition, and diadochokinetic tests. Findings showed that the PSD group and the non-PSD group were most similar for gender, socio-economic status, IQ, and non-word repetition. In the diadochokinetic tasks, the PSD group and the CCD groups were more similar. Implications for these findings in terms of clinical practice are discussed.

The natural history of speech impairment of 8-year-old children in the Avon Longitudinal Study of Parents and Children: Error rates at 2 and 5 years

This prospective longitudinal population study observed the speech of 741 children at the ages of 2, 5 and 8 years. At the age of 8, 132 children were categorized as speech impaired. There was strong evidence of differences between the case and control groups in speech sound error rate at the two earlier age points. The pattern of the proportion of errors was similar for cases and controls. There was evidence of a strong relationship between the childs error rate and expressive language at age 2 and between the childs error rate and sentence length at age 5. In multivariable analyses, adjusting for expressive language, parents social status, maternal age, gender and childs exact age, the increase in odds of being a case as the proportion of errors increased disappeared at 2 years but remained at 5 years. At 5 years, the proportion of speech errors was predictive of ongoing speech errors at the age of 8 years; the adjusted odds of having speech errors at 8 years increased by between 21 and 44% with every 10% rise in the proportion of errors in the target patterns.

A model for a mainstream school-based speech and language therapy service

This report of the Withywood Speech and Language Therapy (WiSaLT) project describes the process of setting up and evaluating a mainstream school-based and -funded speech and language therapy service. Outcomes for the child, the classroom setting, the teacher/therapist relationship and the school as a whole were monitored. Progress towards each of the outcomes was demonstrated but it was found that those children with phonological difficulties made more progress than those with language problems. The reasons for this and implications for the future of the service are discussed.

Prevalence and Predictors of Persistent Speech Sound Disorder at Eight Years Old: Findings From a Population Cohort Study

Purpose The purpose of this study was to determine prevalence and predictors of persistent speech sound disorder (SSD) in children aged 8 years after disregarding children presenting solely with common clinical distortions (i.e., residual errors). Method Data from the Avon Longitudinal Study of Parents and Children (Boyd et al., 2012) were used. Children were classified as having persistent SSD on the basis of percentage of consonants correct measures from connected speech samples. Multivariable logistic regression analyses were performed to identify predictors. Results The estimated prevalence of persistent SSD was 3.6%. Children with persistent SSD were more likely to be boys and from families who were not homeowners. Early childhood predictors identified as important were weak sucking at 4 weeks, not often combining words at 24 months, limited use of word morphology at 38 months, and being unintelligible to strangers at age 38 months. School-age predictors identified as important were maternal report of difficulty pronouncing certain sounds and hearing impairment at age 7 years, tympanostomy tube insertion at any age up to 8 years, and a history of suspected coordination problems. The contribution of these findings to our understanding of risk factors for persistent SSD and the nature of the condition is considered. Conclusion Variables identified as predictive of persistent SSD suggest that factors across motor, cognitive, and linguistic processes may place a child at risk.

Speech characteristics of 8-year-old children: findings from a prospective population study.

UNLABELLED Speech disorder that continues into middle childhood is rarely studied compared with speech disorder in the early years. Speech production in single words, connected speech and nonword repetition was assessed for 7390 eight-year-old children within the Avon Longitudinal Study of Parents and Children (ALSPAC). The majority (n=6399) had typical speech and 50 of these children served as controls. The remainder were categorised as using common clinical distortions only (CCD, n=582) or speech difficulties (SDiff, n=409). The samples from the CCD children were not analysed further. Speech samples from the SDiff and the control children were transcribed and analysed in terms of percentage consonants correct, error type and syllable structure. Findings were compared with those from children in the Shriberg et al. (1997) lifespan database (n=25). The 8-year-old children from ALSPAC in the SDiff and control groups achieved similar speech accuracy scores to the 8-year-old children in the lifespan database. The SDiff group had consistently lower scores than the ALSPAC control group, with the following measures most clearly differentiating the groups: single word task (percentage of substitutions and distortions), connected speech task (percentage of vowels correct (PVC), percentage of omission of singletons and entire clusters, and stress pattern matches), nonword repetition task (PVC, percentage of entire clusters omitted, percentage of distortions, and percentage of stress pattern matches). Connected speech and nonword samples provide useful supplementary data for identifying older children with atypical speech. LEARNING OUTCOMES The reader will recognize the methods used to identify speech characteristics in a large scale population study. They will describe how measures of speech accuracy in connected speech compare with the Shriberg et al. (1997) lifespan database. The reader will also recall information on how typically and atypically developing children differ on a range of measures across different types of speech sample.

Interventions for children with speech, language and communication needs: An exploration of current practice

This article reports a series of interviews with education and health practitioners. The aims were to identify interventions used in practice with children with speech, language and communication needs, to explore explanations for the choice of intervention and to identify the ways that outcomes were measured. Participants (n = 61) included educational psychologists, speech and language therapists and education advisory staff. They talked about interventions in terms of published programmes, principles and activities, strategies, resources and training programmes. There was evidence of local adaptation of interventions and wide development of local programmes. The choice of intervention was governed by a desire to meet identified service gaps and with reference to the evidential and/or theoretical basis of the intervention and the practicalities of the intervention. Outcomes were typically measured at the level of the individual rather than a service level. The study provided insight into the range of interventions in current practice, how service managers justify intervention choices and measure outcomes. The data from this study informed a national survey to examine patterns of usage of interventions.

Cluster-randomized controlled trial evaluating the effectiveness of computer-assisted intervention delivered by educators for children with speech sound disorders

Purpose The aim was to evaluate the effectiveness of computer-assisted input-based intervention for children with speech sound disorders (SSD). Method The Sound Start Study was a cluster-randomized controlled trial. Seventy-nine early childhood centers were invited to participate, 45 were recruited, and 1,205 parents and educators of 4- and 5-year-old children returned questionnaires. Children whose parents and educators had concerns about speech were assessed (n = 275); 132 children who were identified with phonological pattern-based errors underwent additional assessment. Children with SSD and no difficulties with receptive language or hearing, typical nonverbal intelligence, and English as their primary language were eligible; 123 were randomized into two groups (intervention n = 65; control n = 58), and 3 withdrew. The intervention group involved Phoneme Factory Sound Sorter software (Wren & Roulstone, 2013) administered by educators over 9 weeks; the control group involved typical classroom practices. Participants were reassessed twice by a speech-language pathologist who was unaware of the initial assessment and intervention conditions. Results For the primary outcome variable (percentage of consonants correct), the significant mean change from pre- to postintervention for the intervention group (mean change = +6.15, p < .001) was comparable in magnitude to the significant change for the control group (mean change = +5.43, p < .001) with a small between-groups effect size for change (Cohens d = 0.08). Similar results occurred for measures of emergent literacy, phonological processing, participation, and well-being. Conclusion Computer-assisted input-based intervention administered by educators did not result in greater improvement than typical classroom practices.