Effect of prosodic domains and context availability in producing English lexical stress by Korean L2 speakers

The current study examined which acoustic correlates Korean L2 learners of English use in producing English lexical stress in three different prosodic domains. We also examined whether the use of acoustic cues to lexical stress differs as a function of context availability. Considering that English stress pairs consist with noun-verb pairs, we examined whether verbs will be facilitated by given context as compared to noun, since verbs has more abstract semantic meaning than nouns. A total of 30 speakers (15 Koreans, 15 Americans) produced 13 English disyllabic stress pairs in three different carrier sentences (contextually-related sentences, contextually-neutral carrier sentence, and isolated words). F0 and duration of the first and second syllables of the target words were measured. The results revealed that, although Korean speakers were able to produce English stress, their use of acoustic cues was affected by prosodic domains in L1; when the target words were produced as isolated words, F0 and duration were strongly affected by IP-boundary. Regarding context effect, speakers were not influenced by contextual cue in implementing lexical stress. Taken together, this study contributed to understanding how English native speakers and Korean L2 learners use different acoustic correlates in producing English stress, and how those cues differ as a function of different prosodic domains in sentence.