Barbara Dodd

Differential Diagnosis of Pediatric Speech Sound Disorder

Theoretical accounts and clinical management of pediatric speech sound disorders (SSD) are limited by previous research. Participants’ speech difficulties have been inadequately described, reflecting the lack of clarity in existing diagnostic guidelines. Performance measures have primarily focused on the articulation of consonants in single words rather than phonological competence and the cognitive-linguistic abilities underlying speech development. Evidence-based practice reviews conflate studies of heterogeneous speech-disordered populations who received widely differing amounts of therapy using different intervention approaches. More recently, however, researchers have begun to explore assessment measures that allow differential diagnosis of subgroups of SSD in terms of qualitative analyses of speech errors and underlying cognitive linguistic abilities. These measures have allowed long-term follow-up to better predict which children will have future literacy difficulties and to identify specific underlying deficits that inform intervention.

Who to Refer for Speech Therapy at 4 Years of Age Versus Who to “Watch and Wait”?

Objective To examine predictors of speech disorder resolution versus persistence at age 7 years in children with speech errors at age 4 years. Study design Participants were drawn from a longitudinal, community cohort. Assessment at age 4 years (N = 1494) identified children with speech errors. Reassessment at age 7 years allowed categorization into resolved or persistent categories. Logistic regression examined predictors of speech outcome, including family history, sex, socioeconomic status, nonverbal intelligence, and speech error type (delay vs disorder). Results At age 7 years, persistent errors were seen in over 40% of children who had errors at age 4 years. Speech symptomatology was the only significant predictor of outcome (P = .02). Children with disordered errors at age 4 years were twice as likely to have poor speech outcomes at age 7 years compared with those with delayed errors. Conclusions Children with speech delay at age 4 years seem more likely to resolve, and this might justify a “watch and wait” approach. In contrast, those with speech disorder at age 4 years appear to be at greater risk for persistent difficulties, and could be prioritized for therapy to offset long‐term impacts.

Delayed and disordered development of articulation and phonology between four and seven years

Some children’s speech impairment resolves spontaneously. Others have persistent problems affecting academic and social development. Identifying early markers that reliably predict long-term outcome would allow better prioritization for preschool intervention. This article evaluates the significance of different types of speech errors, made by 93 four-year-olds in a longitudinal population cohort study, for performance at seven years. At four years, the non-age appropriate speech errors made on standardized assessments were categorized as: phonologically delayed (error patterns typical of younger children); or, some errors atypical of normal development, including consistent errors (e.g. word initial consonant deletion), inconsistent pronunciations of the same word, or lateral distortion of /s, z/). Delayed children, some with occasional interdental /s, z/ articulation errors, were more likely to resolve (67%) than those making atypical errors (35%) by seven years. Qualitative analyses indicated that children making few atypical errors were more likely to resolve, irrespective of total number of errors or whether they received intervention. The findings’ theoretical implications relate to deficits underlying phonological disorders. Clinical implications concern assessment measures and prioritization for intervention.

Automated screening of speech development issues in children by identifying phonological error patterns

A proof of concept system is developed to provide a broad assessment of speech development issues in children. It has been designed to enable non-experts to complete an initial screening of childrens speech with the aim of reducing the workload on Speech Language Pathology services. The system was composed of an acoustic model trained by neural networks with split temporal context features and a constrained HMM-encoded with the knowledge of Speech Language Pathologists. Results demonstrated the system was able to improve PER by 33% compared with standard HMM decoders, with a minimum PER of 19.03% achieved. Identification of Phonological Error Patterns with up to 94% accuracy was achieved despite utilizing only a small corpus of disordered speech from Australian children. These results indicate the proposed system is viable and the direction of further development are outlined in the paper.

Better in both? Bilingual intervention in an Australian school context

This study evaluated a bilingual intervention in the key learning area of mathematics. Nine typically developing Samoan–English students received math lessons in both Samoan and English. A control group of Samoan–English students received all lessons in English. The material covered and the amount of instruction was the same for each group. The only difference was in the language of instruction. Two assessments measured progress in early mathematical skills and concept development. Initial data from each test in isolation indicated no additional benefit for students who received bilingual intervention. Further analysis revealed two interesting patterns of learning between tests. First, all students more easily acquired rote mathematical skills and knowledge than conceptual knowledge and its associated vocabulary. Second, there were differences in patterns of learning between groups. The control group acquired mathematical skills but made limited progress acquiring conceptual knowledge. In contrast, the intervention group demonstrated more balanced learning: acquisition of core math skills was matched by gains in conceptual development. We propose that bilingual intervention facilitated English word learning, producing improved learning of core skills linked to underlying conceptual knowledge.

The phonological memory profile of preschool children who make atypical speech sound errors

Abstract Previous research indicates that children with speech sound disorders (SSD) have underlying phonological memory deficits. The SSD population, however, is diverse. While children who make consistent atypical speech errors (phonological disorder/PhDis) are known to have executive function deficits in rule abstraction and cognitive flexibility, little is known about their memory profile. Sixteen monolingual preschool children with atypical speech errors (PhDis) were matched individually to age-and-gender peers with typically developing speech (TDS). The two groups were compared on forward recall of familiar words (pointing response), reverse recall of familiar words (pointing response), and reverse recall of digits (spoken response) and a receptive vocabulary task. There were no differences between children with TDS and children with PhDis on forward recall or vocabulary tasks. However, children with TDS significantly outperformed children with PhDis on the two reverse recall tasks. Findings suggest that atypical speech errors are associated with impaired phonological working memory, implicating executive function impairment in specific subtypes of SSD.

Do children with phonological delay have phonological short-term and phonological working memory deficits?

While little is known about why children make speech errors, it has been hypothesized that cognitive-linguistic factors may underlie phonological speech sound disorders. This study compared the phonological short-term and phonological working memory abilities (using immediate memory tasks) and receptive vocabulary size of 14 monolingual preschool children with phonological delay with individually matched peers with typical speech development. The immediate memory tasks examined forward recall of familiar words (pointing response), reverse recall of familiar words (pointing response), and reverse recall of digits (spoken response). The results indicated that children with typical speech development had larger receptive vocabularies and performed significantly better than children with phonological delay on all immediate memory tasks. Qualitative error analyses revealed that while the two groups made similar errors on the forward memory task, children with phonological delayed performed differently on reverse recall of spoken digits. These findings suggest a link between immediate memory and delayed phonological development.

Planning Intervention Using Dynamic Assessments: A Case Study.

Dynamic assessments (DA) of language have been shown to be a useful addition to the battery of tests used to diagnose language impairments in children, and to evaluate their skills. The current article explores the value of the information gained from a DA in planning intervention for a child with language impairment. A single case study was used to demonstrate the detailed qualitative information that can be derived from a DA procedure, and how that information may be used to elicit greater gains from intervention. The participant was a boy, aged 9, with a previously diagnosed language impairment. He was receiving language therapy regularly in a language resource base attached to his school. The CELF-3(UK) was used to monitor changes in his language, before and after two periods of intervention. The initial baseline phase consisted of regular ongoing language therapy. The second phase of therapy was modified by the speech and language therapist after receiving a report of the child’s performance on the Dynamic Assessment of Sentence Structure (DASS; Hasson et al., 2012), and observations of the child’s metalinguistic and metacognitive awareness. Greater gains observed in the second phase of therapy reflected the good modifiability shown by the child’s performance on the DASS.

Articulation or phonology? Evidence from longitudinal error data

ABSTRACT Children’s speech difficulties can be motor (phone misarticulation) or linguistic (impaired knowledge of phonological contrasts and constraints). These two difficulties sometimes co-occur. This paper reports longitudinal data from the Early Language in Victoria Study (ELVS) at 4 and 7 years of age. Of 1494 participants, 93 made non-age appropriate speech errors on standardised assessments at 4 years, and were able to be reassessed at 7 years. At 4 years, 85% of these children only made phonological errors, 14% made both articulation and phonological errors and one child only made articulation errors (a lateral lisp). In total, 8 of 13 children making both articulation and phonological errors at 4 years had resolved by 7 years. Unexpectedly, eight children who had demonstrated articulation of fricatives at 4 years, acquired distorted production of ≥ 50% of occurrences of/s, z/ by 7 years. In total, then, 22 children (24% of children with speech difficulties) made articulatory errors at one or both assessments. Case data for all children are presented. Theoretical and clinical implications are considered.