Contrast, context, and contact: Phonetic variation in the Assamese mid front vowel space

This paper presents a sociophonetic investigation of a contested aspect of Assamese vowel phonology, focusing on the mid front vowel space. Drawing on data from the newly developed COCAS corpus, the study investigates whether there is empirical evidence for the proposed two-way phonemic contrast (/e/ and /ɛ/), or whether mid front vowels are better understood as variable realizations of a single phoneme, and if so, whether such realizations are consistent across all contexts. Findings suggest that Assamese has a single mid front vowel phoneme /ɛ/, with systematic phonetic variation shaped by lexical history, speech style (spontaneous vs. controlled speech), and sociolinguistic ecology. These results challenge standard-based and ahistorical descriptions in earlier analyses, and underscore the importance of sociolinguistically grounded approach, with implications for sociolinguistic accounts of vowel variation in contact ecology.