English with Brazilian beat: Brazilian English word stress and vowel reduction

This study examined vowel reduction as a correlate for word stress assignment in native (L1) and non-native (L2) speakers of American English (AE) through a word reading task. In trisyllabic words, L1 speakers reduced unstressed vowels more in duration than L2 speakers, confirming predictions about temporal vowel reduction. While F0 pitch peaks and vowel quality did not differ significantly between groups, intensity and spectral characteristics of English reduced vowels revealed key distinctions. Both groups used greater intensity for stressed vowels, suggesting that mean intensity is a stress marker. However, L2 speakers produced generally higher mean intensities on stressed vowels, indicating a reliance on non-native phonetic correlates to approximate native-like stress patterns. Spectral analyses showed that L2 speakers did not reduce vowels as narrowly in the F1-F2 space as L1 speakers, likely due to the influence of their native language (Brazilian Portuguese), which does not present spectral reduction. This broader spectral realization suggests a merged L1-L2 acoustic system in bilinguals, where reduced vowels may overlap with full vowel categories. These findings support the view that L2 speakers can achieve phonological targets using different acoustic strategies and highlight intensity and spectral correlates as strong acoustic correlates for word stress, rather than F0, in signaling stress in both L1 and L2 AE productions.