The Covert Contrast in the Acquisition of /u/-/u:/: Production evidence from non-Arabic Speakers

Abstract

Covert contrast refers to the phenomenon in which speakers produce a statistically significant acoustic difference, but native listeners do not perceive it. This study investigates phonemic Arabic vowel contrast (/u/ - /u:/) as produced by native Indonesian and Filipino speakers that is not present in their L1. Through an in-depth analysis of 84 participants, the paper investigates how L2 speakers navigate these phonemes, examining the presence of covert contrast, the relationship between proficiency level and covert contrast. Based on acoustic analysis and native Arabic speakers’ identification, the findings indicated that approximately 35% of participants (58 out of 168 cases) exhibited covert contrast in producing target vowels. This discovery supports the notion that covert contrast constitutes an inherent aspect of the L2 acquisition process. Notably, a positive correlation between proficiency levels and covert contrast suggests a diminishing occurrence of covert contrast with increasing proficiency, leading to a more pronounced presence of overt contrast. This observation supports the proposition that the acquisition process follows a graduated trajectory in the realization of /u:/, which is absent in their L1. The finding also offers specific insights into how L1 impacts L2 phonemic acquisition. Lastly, the reliable acoustic cue that L2 speakers relied on was the vowel duration rather than F1 and F2. The findings have implications for language acquisition, underscoring the importance of recognizing the presence of covert contrast in L2 acquisition as a crucial intermediate stage for achieving phonological mastery. Moreover, the findings align cohesively with both the Speech Learning Model (Flege, 1995), highlighting the overarching influence of NL characteristics on challenges encountered by L2 speakers in L2 acquisition.