Gestural restructuring beyond coarticulation in Korean /w/-vowel sequence Evidence from phonetic, dialectal, and gender variation

Abstract

This study examines the articulatory patterns of Korean /w/-vowel sequences by comparing tongue dorsum movement trajectories with those of corresponding plain vowels, using Electromagnetic Articulography data from 48 speakers of Seoul and North Gyeongsang dialects. The central question is whether these sequences reflect mere coarticulation or exhibit signs of gestural restructuring in the nucleus vowel. Results reveal gradient restructuring shaped by vowel constriction degree, dialect, and gender. High vowels (/wi/-/i/) show minimal divergence, mid vowels (/we/-/e/, /w epsilon/-/epsilon/) moderate divergence, and low back vowels (/wa/-/a/, /w Lambda/-/Lambda/) the greatest divergence-especially in dialect- and gender-specific ways. Further analysis of the /e/-/epsilon/ merger and the recent /Lambda/-/i/ split in North Gyeongsang sheds light on how vowel distinctions interact with /w/. The /we/-/w epsilon/ pair shows a stronger merger than /e/-/epsilon/, supporting the view that /w/ triggers gestural restructuring of the nucleus vowel and thus plays an active role in reshaping merger trajectories. This effect is further illustrated by the /wa/-/w Lambda/ and /a/-/Lambda/ contrasts, with a stronger merger in the /w/-initial context-an effect notably led by male speakers. Interestingly, North Gyeongsang males preserve the /a/-/Lambda/ contrast more robustly than the /wa/-/w Lambda/ contrast, possibly due to hyperarticulation of a phonetically redefined /Lambda/ resulting from the recent /Lambda/-/i/ split. These findings are interpreted within a dynamical framework of gestural blending strength (GBS), which varies by vowel constriction and coarticulatory resistance but remains stable for /w/. Overall, the results suggest that what may have begun as low-level coarticulation has evolved into systematic gestural restructuring-a gradient shift toward phonological reorganization shaped by phonetic context, sound change, and sociophonetic variation.