The acoustics of the alignment of focus prosody and lexical stress: A production study of native speakers and second language learners of English

Abstract

In English, the tonal target of a pitch accent is aligned with lexical stress. Therefore, the phonetic realization of contrastive focus prosody, phonologically marked by a H*/L + H* pitch accent, is expected to vary depending on the stress pattern of the focused word. This study explored acoustic effects of the alignment of lexical stress and focus prosody and examined how it is learned by Korean learners of English, whose first language lacks lexical stress. Ten native English speakers (L1) and 19 Korean learners of English (L2) participated in a read-aloud task, in which they produced nine trisyllabic words with primary stress on one of the three syllables with contrastive focus (e.g., Animal, vaNILla, engiNEER). For each syllable, three acoustic measures were extracted: the height of pitch peak, periodic energy mass, and the direction of pitch movements (Albert et al., 2021; Cangemi et al., 2019). Results revealed that the height of pitch peak, a conventional measure of both lexical stress and contrastive focus, did not properly demonstrate their alignment. Instead, the stressed syllable of the focused words was marked by its overall prominence (mass) or the direction of pitch movements, depending on the stress pattern. The L2 speakers’ productions were similar to the L1 productions, but there were indications of an influence of their L1 prosody and English proficiency. [This work was supported by the Ministry of Education and the National Research Foundation of Korea (NRF-2022S1A5A8052482).]