L2 Perception of English Fricatives in Clear and Conversational Speech: the Role of Phonemic, Phonetic, and Acoustic Factors

This study investigated perception by non-native listeners of English fricatives produced in clear and conversational speaking styles. We measured babble thresholds for fricative voicing and place of articulation contrasts by Standard German and Swabian German and native American English speakers. Overall, Swabian German speakers performed worse than both native English and Standard German speakers, and Standard German speakers worse than native English speakers. German speakers in general had more difficulty with non-sibilant distinctions, and Swabian speakers also had difficulty with sibilant voicing distinctions. A robust clear speech benefit was observed across groups and contrasts. Overall, the results indicate that difficulty in perceiving foreign-language contrasts stems from the interaction of phonological, phonetic, and psychophysical issues.