Developing and validating a Sinhala phonology assessment for children aged between 3 to 6 years: trends observed and lessons learnt

Abstract

Clinical experience of speech and language therapists working in Sri Lanka has put into question the current reliance on norms for English (Grunwell, 1985) to determine a child’s speech skills and phonological acquisition in Sinhala. Cross-linguistic studies have revealed differences in ‘universal principles’ and ‘language-specific’ aspects (Amayreh & Dyson, 1998). At present, there is an urgent need to develop and validate formal language-specific standardized assessments for speech and phonology for Sinhala. The aims of the study were; 1)to develop and validate test items for a Sinhala speech and phonology assessment for children aged between 3;0 to 6;0 years, 2)to document the typical phoneme acquisition and typical phonological processes in Sinhala-speaking children aged between 3;0 to 6;0 years. The ‘Sinhala Speech and Phonology Assessment’ was devised based on the Diagnostic Evaluation of Articulation and Phonology (Dodd et al. 2002) and administered to 250 Sinhala-speaking children between the ages 3;0 to 6;00 years. The use of test items were determined by measures of content validity, test-retest reliability and inter-rater reliability. The trajectory of Sinhala speech sound acquisition showed universal sound acquisition sequences and language-specific features in both the order and rate of speech sound development. The sequence of speech sound acquisition for Sinhala showed early acquisition of plosives and some nasals with comparatively later acquisition of fricatives, the palatal nasal and flap/tap sound. Language-specific phonological processes of lateralization and denasalisation of prenasalised stops were also evident. The test items demonstrated effectiveness at generating target speech data and typical phoneme and phonological development in children between 3;0 to 6;0.