Abstract
<jats:title>Abstract</jats:title> <jats:p>The Bahnar language, a member of the Northern Bahnaric branch of the Mon-Khmer family, shows distinctive register contrasts that provide important insights into the process of registrogenesis. This paper studies register variation across three major dialects of Bahnar (spoken in Bình Định, Gia Lai and Kon Tum provinces of Vietnam) based on production acoustic data collected from 48 native speakers. The authors analyze several phonetic parameters, including fundamental frequency (F0), vowel quality, voice quality, voice onset time (VOT) and vowel duration and focus on the correlation between initial consonants and the following vowels. The findings show clear dialectal differences: Bình Định displays a particularly lower register and complex devoicing patterns in initial consonants, while Gia Lai and Kon Tum rely more on spectral and temporal cues. These patterns suggest that Bahnar is experiencing transphonologization, with registers compensating for the weakening of initial consonant voicing. Beyond collecting regional variation data, the paper also explores sociophonetic variation. It contributes to the understanding of the phonetic mechanisms that drive registrogenesis in Austroasiatic languages and highlights the role of social factors in influencing Bahnar phonology.</jats:p>