Mapping Out the Acoustic Predictors for the Perceived Accentedness and Comprehensibility of Cantonese Checked Syllables

This study examines the acoustic correlates of accentedness and comprehensibility in Cantonese checked syllables produced by Mandarin-speaking learners. Forty learners produced four checked syllables (luk6, cat1, baat3, and sap6), which were evaluated by native Cantonese listeners. Generalized additive mixed models (GAMMs) were used to examine potentially non-linear associations between listener ratings and acoustic measures of vowel quality, pitch contour, duration, and voice quality. Results show that while listener ratings of accentedness and comprehensibility were highly correlated, their acoustic correlates varied substantially across syllables. After correction for multiple comparisons, vowel duration was the only acoustic measure significantly associated with listener ratings, with effects observed for both perceptual dimensions in luk6 and baat3. For luk6, relatively prolonged realizations were associated with lower ratings on both perceptual dimensions, whereas for baat3, longer realizations were associated with higher ratings. No acoustic measure remained significant for cat1 or sap6. These findings suggest that the relationship between acoustic properties and listener evaluations of Cantonese checked syllables is strongly syllable-specific rather than governed by a common hierarchy of acoustic cues. More broadly, they highlight the importance of examining fine-grained acoustic–perceptual relationships at the level of individual phonological items in L2 tonal speech.