ACQ Vol 13 No1 2011

Language disorders

The effect of two different types of intervention on cluster production in children with speech and language impairment Cecilia Kirk, Gail T. Gillon, and Megan Hide

This small-scale study examined the effectiveness of two different goal attack strategies on four children with speech and language impairments. Of particular interest was the effect of the two types of intervention on the production of consonant clusters. It was hypothesised that the two children who received instruction in phonological awareness skills integrated with speech production practice would show greatest improvement in word-initial clusters. It was further hypothesised that the two children who received intervention that focused primarily on morphological structures at the ends of words, alternating with sessions focusing on speech targets would show greatest improvement in word-final clusters. The participants who received phonological awareness and speech intervention made the greatest improvement in cluster production, although this difference was most noticeable in clusters not directly targeted by either intervention. These results suggest that integrating speech production practice with phonological awareness instruction may lead to better generalisation to non-target phonological structures. M any preschoolers who receive clinical services from speech pathologists (SPs) have co-occurring speech and language impairments. Estimates of the co-morbidity of speech and language deficits in this population are as high as 60–75% (e.g., Paul & Shriberg, 1982). However, surprisingly little is known about how to best treat children who have impairments in both speech and language. Research by Tyler, Lewis, Haskill, and Tolbert (2003) investigated the efficacy of different goal attack strategies for children with both speech and language impairments. These researchers addressed the question of whether it is more effective for intervention to alternate between the domains of phonology and morphosyntax or whether a single domain should be selected as the focus of intervention, with the

expectation that cross-domain generalisation will occur. Tyler et al. (2003) found that phonological performance was facilitated equally by three types of goal attack strategy: phonological intervention alone, morphosyntax intervention alone, and intervention that alternated weekly between the domains of phonology and morphosyntax. In addition, morphosyntax intervention alone and intervention that alternated between phonological and morphosyntactic goals led to better morphosyntactic performance than phonological intervention alone. The current study takes two of the goal attack strategies investigated by Tyler et al. (2003) and assesses their effect on the production of consonant clusters by children with co-occurring speech and language impairments. One intervention program focused on sounds at the beginnings of words using therapy that integrated speech production practice with instruction in phonological awareness skills and letter knowledge (phonological awareness and speech [PAS] intervention). The other intervention program focused predominantly on morphological structures at the ends of words, alternating weekly with sessions that focused on the children’s speech targets. The purpose of the study was to determine whether the two intervention programs differentially impacted the production accuracy of three different types of consonant clusters: word-initial clusters that had been directly targeted by the PAS intervention, word-final clusters that had been indirectly targeted by the morphosyntax and speech (MS) intervention, and word-initial clusters that had been neither directly or indirectly targeted by either intervention. Although it would also be of great interest to compare the effect of the two intervention types on the development of morphological structures, this is outside the scope of the current article. The acquisition of consonant clusters is one of the most protracted aspects of children’s speech development. Preschool children with a speech sound disorder are very likely to struggle with the correct production of consonant clusters (McLeod, van Doorn, & Reed, 1997). In addition, consonant clusters occur with high frequency in English words. One-third of monosyllabic words in English begin with a consonant cluster and an even higher proportion end with a consonant cluster (Locke, 1983). Because of their high frequency, the mispronunciation of consonant clusters has potential to negatively impact speech intelligibility. Therefore, it is critical to investigate the most effective way of improving the production of consonant clusters in children with speech impairment.

Keywords PRESCHOOLERS SPEECH AND LANGUAGE

IMPAIRMENT CONSONANT

This article has been peer- reviewed CLUSTERS PHONEME AWARENESS INTERVENTION MORPHOSYNTAX INTERVENTION

Cecilia Kirk

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ACQ Volume 13, Number 1 2011

ACQ uiring knowledge in speech, language and hearing