Acoustic Evidence for the Tenseness and Laxity Distinction in Hijazi Arabic: A Pilot Study Using Static and Dynamic...

Standard Arabic has a simple three-vowel system with short and long distinctions, specifically /i iː a aː u uː/, traditionally believed to differ solely in duration. However, studies on regional Arabic dialects using a static approach (e.g., measuring formant values at the vowel's midpoint) have suggested that these vowels differ in both quality and quantity. This study aimed to investigate whether Hijazi Arabic (HA) exhibits a tense/lax distinction and, importantly, whether a dynamic analysis (particularly Vowel Inherent Spectral Change) could better capture this distinction, an area relatively underexplored in Arabic acoustic studies.

Data were collected from 20 native HA speakers, who produced six HA vowels in various consonantal environments. The first two formant values and vowel duration were automatically extracted. Static formant values were measured at the vowel's midpoint, while dynamic spectral changes were measured at three points during the vowel's duration.

The findings revealed a significant distinction between short and long HA vowels, not only in duration but also in their acoustic properties. In the static model, short vowels were more centralized, while long vowels were more peripheral. In the dynamic model, the spectral changes of short vowels differed significantly from those of their long counterparts.

These results underscore the existence of a tense/lax distinction in HA, challenging the traditional view that the distinction is based solely on duration. They also highlight the value of dynamic vowel analysis for a comprehensive understanding of vowel behavior in phonological systems.