Kinematic signatures of ternary quantity in Estonian prosodic structure

This study investigates the kinematic correlates of Estonian's phonemic length system, focusing on how foot-level prosodic structure interacts with quantity distinctions operative at the segment and syllable levels. Estonian is typologically rare in exhibiting a three-way quantity contrast (short, long, overlong) that spans segments, syllables, and feet. While this contrast is phonologically restricted to stressed syllables, it has systematic timing effects on adjacent unstressed syllables within the foot. Using Electromagnetic Articulography (EMA), we examine how these phonemic length categories are reflected in articulatory kinematics—the duration, displacement, and velocity of constriction gestures—across different foot types (disyllabic versus trisyllabic; primary versus secondary). Data were collected from 20 native speakers producing two-, three-, and four-syllable words with initial vowels varying in quantity (V, VV, VVV), embedded in frame sentences with controlled prosodic environments. We assess how kinematic profiles vary with segmental quantity, foot structure, and stress distribution, and compare these patterns to those observed for stress and accent in other languages. This work contributes to a dynamical systems perspective on prosody, treating speech rhythm as emerging from interacting oscillatory systems across multiple temporal scales. The findings provide new insight into how Estonian’s unique prosodic system is implemented in the articulatory domain.