Production and perception of Korean and English word-level prominence by Korean speakers

Abstract

Prominence refers to the relative emphasis that may be given to a syllable in a word (word-level prominence) or to one or more words in a phrase (phrase-level prominence). Korean has been claimed to have both word-level (Ko, 2013) and phrase-level (Jun, 1996) prominence, with the former realized mainly with duration and the latter with F0 height. However, given the claim that younger Korean speakers have lost duration as the main cue expressing word-level prominence (Kim & Han, 1998; Magen & Blumstein, 1993), it is not clear if and how younger Korean speakers produce word-level prominence. Thus, the primary goal of the current dissertation is to examine whether Korean still has word-level prominence. Two experiments investigated this research question in two domains – acoustically (Experiment 1) and perceptually (Experiment 2). Given the findings regarding the status of lexical stress in Korean, we further investigated which acoustic correlates/cues Korean learners of English are able to transfer from their L1 prosodic cues, and whether they can acquire a new cue that does not exist in their L1. Thus, the secondary purpose of this study is to investigate which acoustic correlates/cues Korean L2 learners of English utilize in producing and perceiving English lexical stress. These questions are addressed and examined in Experiments 3 and 4. In the acoustic study of the production of Korean word-level prominence (Experiment 1), measurements of duration, intensity, F0, F1, and F2 on (so-called) Korean stress minimal pairs by older and younger Korean speakers revealed that only at the sentence level, duration and intensity systematically distinguish stress pairs for the older speakers. A perception study on word-level prominence in Korean (Experiment 2) revealed that both older and younger Korean listeners weighted the duration cue most heavily in identifying minimal pairs of Korean word-level prominence when two of the suprasegmental cues were orthogonally manipulated in each syllable. Interestingly, this perceptual weighting was only observed in the first syllable: none of the listeners changed their perception when cues were signaling second-syllable stress. Based on these findings from an acoustic and a perception study, we conclude that Korean does not have word-level prominence, but only has a phonemic vowel length distinction. In the acoustic study on the production of English word-level prominence (Experiment 3), measurements of duration, intensity, F0, F1, and F2 on English stress pairs found that Korean learners were able to use not only all suprasegmental cues to indicate lexical stress in English, but also acquire a new cue (e.g., vowel reduction) that does not exist in their native language, although in a non-native like manner. The results of the perception study on word-level prominence in English (Experiment 4) revealed that when identifying English stress pairs, Korean learners weighted vowel reduction more heavily than any suprasegmental cues. Both intensity and F0 were weighted in Korean learners’ perception; however, duration was not weighted at all, although younger Korean speakers still retain the phonemic vowel length distinction in their L1. Taken together, the current dissertation increases our understanding of the status of lexical stress in Korean, as well as the extent to which L2 learners produce and perceive L2 lexical stress by transferring prosodic features from their native language.