This study investigates how phonological and phonetic aspects of the native-language (L1) intonation modulate the use of tonal cues in second-language (L2) speech segmentation. Previous research suggested that prosodic learning is more difficult if the L1 and L2 intonations are phonologically similar but phonetically different (French–Korean) than if they are phonologically different (English–French/Korean) (Prosodic-Learning Interference Hypothesis; Tremblay, Broersma, Coughlin & Choi, 2016). This study provides another test of this hypothesis. Korean listeners and French-speaking and English-speaking L2 learners of Korean in Korea completed an eye-tracking experiment investigating the effects of phrase tones in Korean. All groups patterned similarly with the phrase-final tone, but, unlike Korean and French listeners, English listeners showed early benefits from the phrase-initial tone (signaling word-initial boundaries in English). Importantly, French listeners patterned like Korean listeners with both tones. The Prosodic-Learning Interference Hypothesis is refined to suggest that prosodic learning difficulties may not be persistent for immersed L2 learners.

This study newly investigates whether the functional weight of a prosodic cue in the native language predicts listeners’ learning and use of that cue in second-language speech segmentation. It compares English and Dutch listeners’ use of fundamental-frequency (F0) rise as a cue to word-final boundaries in French. F0 rise signals word-initial boundaries in English and Dutch, but has a weaker functional weight in English than Dutch because it is more strongly correlated with vowel quality in English than Dutch. English- and Dutch-speaking learners of French matched in French proficiency and experience, and native French listeners completed a visual-world eye-tracking experiment in French where they monitored words ending with/out an F0 rise (replication of Tremblay, Broersma, Coughlin & Choi, 2016). Dutch listeners made earlier/greater use of the F0 rise than English listeners, and in one condition they made greater use of F0 rise than French listeners, extending the cue-weighting theory to speech segmentation.