Early hearing loss and language abilities in children with Down syndrome

BACKGROUND: Although many children with Down syndrome experience hearing loss, there has been little research to investigate its impact on speech and language development. Studies that have investigated the association give inconsistent results. These have often been based on samples where children with the most severe hearing impairments have been excluded and so results do not generalize to the wider population with Down syndrome. Also, measuring children's hearing at the time of a language assessment does not take into account the fluctuating nature of hearing loss in children with Down syndrome or possible effects of losses in their early years. AIMS: To investigate the impact of early hearing loss on language outcomes for children with Down syndrome. METHODS & PROCEDURES: Retrospective audiology clinic records and parent report for 41 children were used to categorize them as either having had hearing difficulties from 2 to 4 years or more normal hearing. Differences between the groups on measures of language expression and comprehension, receptive vocabulary, a narrative task and speech accuracy were investigated. OUTCOMES & RESULTS: After accounting for the contributions of chronological age and nonverbal mental age to children's scores, there were significant differences between the groups on all measures. CONCLUSIONS & IMPLICATIONS: Early hearing loss has a significant impact on the speech and language development of children with Down syndrome. Results suggest that speech and language therapy should be provided when children are found to have ongoing hearing difficulties and that joint audiology and speech and language therapy clinics could be considered for preschool children.

Common variance in amplitude envelope perception tasks and their impact on phoneme duration perception and reading and spelling in Finnish children with reading disabilities

Our goal was to investigate auditory and speech perception abilities of children with and without reading disability (RD) and associations between auditory, speech perception, reading, and spelling skills. Participants were 9-year-old, Finnish-speaking children with RD (N = 30) and typically reading children (N = 30). Results showed significant group differences between the groups in phoneme duration discrimination but not in perception of amplitude modulation and rise time. Correlations among rise time discrimination, phoneme duration, and spelling accuracy were found for children with RD. Those children with poor rise time discrimination were also poor in phoneme duration discrimination and in spelling. Results suggest that auditory processing abilities could, at least in some children, affect speech perception skills, which in turn would lead to phonological processing deficits and dyslexia.

Predicting dyslexia using prereading skills:the role of sensorimotor and cognitive abilities

Background: It is well established that phonological awareness, print knowledge and rapid naming predict later reading difficulties. However, additional auditory, visual and motor difficulties have also been observed in dyslexic children. It is examined to what extent these difficulties can be used to predict later literacy difficulties. Method: An unselected sample of 267 children at school entry completed a wide battery of tasks associated with dyslexia. Their reading was tested 2, 3 and 4 years later and poor readers were identified (n = 42). Logistic regression and multiple case study approaches were used to examine the predictive validity of different tasks. Results: As expected, print knowledge, verbal short-term memory, phonological awareness and rapid naming were good predictors of later poor reading. Deficits in visual search and in auditory processing were also present in a large minority of the poor readers. Almost all poor readers showed deficits in at least one area at school entry, but there was no single deficit that characterised the majority of poor readers. Conclusions: Results are in line with Pennington’s (2006) multiple deficits view of dyslexia. They indicate that the causes of poor reading outcome are multiple, interacting and probabilistic, rather than deterministic. Keywords: Dyslexia; educational attainment; longitudinal studies; prediction; phonological processing.