The development of speech sounds and phonetic complexity in Urdu-speaking children

Abstract

Urdu belongs to the central zone of Indo-Aryan languages. It is the 10th most spoken language, with over 230 million speakers worldwide (Eberhard et al., 2022). It is also the national language and lingua franca of Pakistan. Despite having a large population of speakers around the world, Urdu is comparatively under-explored in terms of its speech sound acquisition. This project aimed to explore these acquisition patterns in typically developing Urdu-speaking children. To achieve this, several studies were conducted, which are presented in this thesis. The first study provided a detailed review of the available studies focusing on different aspects of the Urdu phonological system. It discussed consonants, vowels, syllable structures, and phonotactic constraints. Based on the findings, an updated contemporary Urdu inventory was proposed. The second study was a systematic review of studies conducted on Urdu phonological/speech sound development from the past 40 years. Through the systematic online and manual search, a total of 873 records were located. From this, nine studies fulfilled the criteria and were reviewed for research design, study location, sample elicitation methods, the targeted aspects of speech sound development, the transcription systems, and major findings. This review highlighted the strengths and weaknesses in the methodologies employed by these studies while also highlighting the underexplored aspects of Urdu acquisition. The findings from Studies 1 and 2 guided the development of Urdu speech sound assessment test (USAT). Study 3 provided a detailed discussion of USAT’s conceptualization and operationalization processes which was developed to elicit all Urdu consonants and vowels with sufficient coverage (production opportunities), in phonetically controlled contexts. It was used for data collection in the subsequent studies conducted as part of this project. Study 4 had two parts. The first part explored the typical adult productions of all Urdu consonants and vowels, which were used in the second part that focused on the speech sound acquisition in 2;7–6;0 years old Urdu-speaking children. USAT was used to elicit the speech samples from 208 children. These samples were analyzed to explore: the age of phoneme acquisition; phoneme accuracy patterns; occurrence of phonological processes; and the non-adult realizations of Urdu phonemes. The effects of age on phoneme accuracy were explored. Study 5 focused on the adaptation of the Index of Phonetic Complexity (IPC) for Urdu, which was used in Study 6 to explore the developmental patterns of phonetic complexity in Urdu-speaking children. The data collected from Urdu-speaking children were scored for complexity. P-IPC-Ur scores provided information about the developmental patterns across the studied age. IPC-Ur ratio and absolute differentials were analyzed to compare how the complexity of child productions develops in comparison to the target. Finally, Comp-Acc was used to explore the developmental patterns in child productions while considering phonetic complexity and accuracy together. This project provided updated information regarding different aspects of the Urdu phonological system and its acquisition in typically developing children. The assessment tools developed (USAT) and adapted (IPC-Ur) for Urdu, carefully considered language-specific aspects. These tools and the reported findings can support the provision of clinical services to the Urdu-speaking population. The availability of these two tools could also assist in further research exploring different factors related to Urdu speech sound acquisition.