Patterns of acquisition of sound segments and phonological processes among children aged 3-5:11 years in Nairobi, Kenya

Abstract

Speech and language pathologists (SLP) depend on a normative data when assessing and diagnosing client’s speech disorders and when choosing intervention targets. This is presented in form of a checklist showing a pattern of acquisition of sound segments. Though the availability of normative data is a necessity, any SLP assessing a Kenyan child on speech sounds development is not at present able to make any clinical judgment. This is because there seems to be no cultural and linguistically relevant norms/checklists that have been established for assessing Kenyan children and this may lead to misdiagnosis. This research reports on the pattern of acquisition of sound segments and phonological processes realized by children in Nairobi, Kenya in the ages of 3- 5years, 11month clients were subdivided into six age levels which represented a six- month period of development. Its objectives were to: determine the pattern of phonemic acquisition in six different age levels, identify the pattern of phonemic acquisition in relation to sex and to establish the pattern of phonological processes in operation. The study used Mowrer’s autism theory which explains how children learn speech sounds through imitating their parents as demonstrated in clarity of speech with advancement in age. This aided in the analysis of acquisition of speech sounds in all age levels. Data was collected in eight Early Years Education Centres and one home where there is a variety of children speaking various first languages. This was done using questionnaires, assessment and audio recordings. A standardized assessment tool called South Tyneside Analysis of Phonology (STAP) was used in the study. It consists of coloured pictures of objects. During assessment, each child named the pictures and the target phoneme was recorded either in initial, medial or final position. Quasi-experimental design was used with specific focus on randomized block design and speech samples of 144 children were collected. During data analysis, One- way ANOVA was used to determine the significant difference between the means of six age groups and T-test was used to test acquisition of phonemes according to sex. Descriptive survey was used to analyse phonemes realized. A phoneme was labelled mastered at a particular age level if 90% and above of the clients within an age group correctly produce the target sound. This meant an average of the three sound elements (I, M, F) of each phoneme is realized correctly by ≤90% of all children in an age group. The study revealed that the sequence of sound acquisition of single consonants /p, b, t, k, g m, n, f, w, / were the first to be acquired and the age of acquisition of cluster consonants /sw, sm, sp, bl, sn, fr/ is not later than 4years, 5months. Phonological processes realized are depalatization, voicing, cluster reduction, epenthesis, and stopping. The study also found that some phonemes are mastered earlier by one sex and later by the other. This implies that an SLP should consider both age and sex since some sounds are acquired earlier or later in the age dependinf on sex.