A Cross-Language Comparison of Length Perception in Italian-Learning Adults

This study investigates how adult learners perceive segmental length in L2 Italian. We tested 104 learners from 5 L1 backgrounds that differ in their phonological treatment of quantity: Finnish (vowel and consonant length), Czech and Slovak (vowel length), German (restricted vowel length), and Spanish (no phonemic length). These groups were compared with 34 native speakers of Italian, a language with distinctive consonant length (e.g., papa 'Pope' vs. pappa 'porridge'). Using an AX discrimination task with 45 pseudowords, we examined the influence of L1, stress position, consonant type, and proficiency. The results reveal that L1 strongly predicts perceptual sensitivity to consonantal length contrasts: Finnish learners showed the highest sensitivity, followed by Slovak, Czech, German, and Spanish learners. Discrimination of vowel-length contrasts was weaker across all groups and showed more variation, likely because in Italian, vowel duration does not cue phoneme identity. Stress position also played a significant role: discrimination of consonantal quantity contrasts was most robust in post- and pre-stressed syllables and weakest in unstressed contexts. Consonant type further influenced performance, with quantity being easier to discriminate in sonorants than in obstruents, although L1-specific effects emerged. Proficiency did not emerge as a uniform global predictor, but descriptive patterns indicated higher performance among advanced learners than among beginner-level and intermediate-level learners. Overall, the multifactorial analysis highlights the role of L1 in shaping learners' perception of L2 length, alongside prosodic effects, segmental properties, and proficiency. The study also underscores the importance of perceptual training in acquiring new phonological contrasts.