Acoustic Realization of English Word Stress Produced by English and Korean Speakers: Suprasegmental and Segmental Differences

This study examines how Korean-speaking learners of English produce English word stress in comparison to native English speakers. Participants were trained with nonword stress-minimal pairs (e.g., /ˈkʌnædʒau/ vs. /kʌˈnædʒu/) that do not carry reduced vowels in unstressed syllables. Acoustic-phonetic analyses on the suprasegmental and segmental correlates of English word stress revealed that Korean-speaking learners of English were very similar to native English speakers in their production of suprasegmental cues, with longer duration, higher fundamental frequency (F0), and greater intensity in stressed syllables than in unstressed syllables. However, compared to native English speakers, Korean speakers produced smaller vowel spaces. In addition, unlike native English speakers who often reduced vowels in unstressed syllables (e.g., schwa and its variants), Korean-speaking learners of English didn’t make significant vowel quality change in unstressed syllables. These findings indicate that, even with the exposure to L2 English dominant environment, Korean speakers’ production of English word stress is still influenced by L1 phonology at both suprasegmental and segmental levels.