Presentation

Development of Brazilian Portuguese vowels by an Argentinean learner: A longitudinal case study using Bayesian GAMMs

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Abstract

This study investigated the impact of explicit instruction on the pronunciation of Brazilian Portuguese (BP) mid vowels by an Argentinean learner (L1 Spanish, L2 English, L3 BP) over the course of one year. The participant took part in 24 biweekly data collection sessions. Between sessions 10 and 15, instruction focused on the pronunciation of the vowels /e–ɛ/ and /o–ɔ/. To assess instructional effects, we compared the participant’s BP vowel productions with their Spanish baseline productions using Mahalanobis distances that captured F1, F2, and duration values. Developmental trajectories were analyzed using Bayesian generalized additive mixed models (GAMMs). Results showed that vowel development was not uniform, with the back mid vowels /o–ɔ/ showing most changes, particularly after the instruction period. These findings highlight the potential of pronunciation instruction to influence L3 phonological development.

Keywords: Bayesian GAMM, vowels, longitudinal, second language, pronunciation, Brazilian Portuguese

How to Cite:

Lima Jr., R., & Alves, U. (2026). Development of Brazilian Portuguese vowels by an Argentinean learner: A longitudinal case study using Bayesian GAMMs. In P. Trofimovich, A. Bodea, T.-N. N. Le, R. Suzuki, & C. Teló (Eds.), Proceedings of the 16th Pronunciation in Second Language Learning and Teaching Conference (pp. 1–13). Concordia University, Montreal, Canada, October 2025. https://doi.org/10.31274/psllt.21329