A crosslinguistic corpus phonetic analysis of intrinsic vowel duration

This study investigated the crosslinguistic distribution of intrinsic vowel duration, the observation that high vowels tend to be shorter than low vowels. Using a large-scale corpus phonetic analysis, we analyzed duration contrasts among /i/, /u/, and /a/ in inter-obstruent contexts from over 60 languages and 16 language families in the VoxCommunis Corpus. Across languages, high vowels were shorter than low vowels in approximately 90% of comparisons, while no systematic durational asymmetry was observed between high front and high back vowels. The directional consistency of the height effect, along with a positive correlation between duration and F1 within low vowels, provides support for a biomechanical basis to the effect. However, we argue that an automatic biomechanical source critically depends on the assumption of uniform phonetic targets associated with the shared vowel feature that, when instantiated across different vowel height configurations, allow biomechanical factors to generate the observed durational pattern. Variation in the magnitude of the effect across languages and speakers, as well as some minor relationships between the height effect and vowel inventory size provide some limited support for contrast enhancement. Overall, these findings support intrinsic vowel duration as a robust statistical phonetic universal grounded primarily in a biomechanical source, while target uniformity makes explicit the phonetic target structure that allows the pattern to emerge.