Abstract:
Recent studiesof human infant vocal behaviour haveshown an influence of the ambient language on the early stages of vocalizations. The influence of the ambient language has a certain subset of vocalizations of which can be produced with their vocal tract (MacNeilage& Davis, 2001). In this context, it isquite essential to gain insights into the vocal tract articulatory dimensions of infants. This would suggest some developmental check that may shape speech acquisition. Present paper is focused on the appearances of vowels and diphthongs during early exploration period of babbling extending till 12 months of age in infants of native Malayalam speaking families. The participants comprised of 20 infants, 5 girls each in the age range 4 to 12 months from native Malayalam (A Dravidian language spoken in Southwest of India) speaking families. The audio recorded babbling data of the participants were analysed using IPA (2005) to obtain the frequency and type of vowel and diphthong utterances. Vowels were classified according to tongue height and tongue advancement dimensions. Diphthongs were classified according to the degree of opening or/and closing positions. On statistical analysis, results for tongue height and tongue advancement dimensions, the frequency of occurrence was high for mid front vowels followed by low centre vowels and least for high back vowels. Overall results indicated a reduction in the singleton vowels and diphthongs in infants of older age range indicating emergence of more complex syllabic patterns and word forms in them. These findings on normal phonological development would be highly relevant for clinical practice in the area of communication disorders in young infants.