Exploring Acoustic Overlap in Second Language Vowel Productions

ABSTRACT This study examines the alignment of vowel categories between second language (L2) learners and first language (L1) speakers of the target language, as well as potential overlaps between adjacent vowels in terms of formant frequencies and duration. It involved adult L2 English learners with a Cypriot Greek L1 background who were enrolled in English language and literature courses. Participants engaged in a speech production task and were asked to articulate English vowels within carrier phrases. Bayesian analysis revealed distinct reorganizations in L2 vowel categories. Notably, adjacent vowels, forming perceptually challenging L2 contrasts, exhibited overlaps in at least one acoustic measure. These findings propose a refinement in understanding L2 learners’ challenges, advocating an “overlap—no overlap” framework for adjacent L2 categories, rather than a “fit—no fit” approach, which assesses how L2 productions align with corresponding L1 productions. The results also showed that the production of each vowel was based on different cue weights and that L2 vowel acquisition was not uniform across different vowel pairs. Apart from affirming some support for the premises of the Universal Perceptual Model, this research contributes to the small but emerging discourse on English vowel production by Cypriot Greek learners, enriching the existing body of knowledge in this domain.