This project examines the perception of English lexical stress (e.g., “desert” vs. “dessert”) by listeners from various language backgrounds in order to advance several important questions about the nature of speech perception and learning. The sound system of a person's native language influences not only how second-language learners produce words but also how they recognize words, making it difficult for second-language learners to hear sound contrasts that do not distinguish words in the native language or that differ in how they distinguish words in the native and second languages. These difficulties can in turn impact second-language learners’ ability to understand speech in their second language, thus causing important communication breakdowns, and they can exacerbate the degree of foreign accent that second-language learners typically evidence in speech production. This project seeks to clarify and explain the nature of this native-language influence by investigating a linguistic phenomenon that plays a critical role in spoken-word recognition across languages but has been under-investigated: lexical stress.

The project’s specific goals are threefold. First, the project will elucidate whether the cue-weighting theory of speech perception can provide a strong theoretical framework for understanding the listening difficulties that second-language learners encounter with lexical stress, and for developing training stimuli and methods to enhance the perceptual learning of lexical stress. Second, it will help resolve theoretical debates about the mechanisms underlying second-language perceptual learning, the nature and robustness of second-language perceptual representations, and the degree to which adult second-language perceptual learning remains malleable. Third, it will provide a theoretical foundation for the teaching of second-language speech perception, enabling instructors to tailor teaching practices according to students’ native language and individual abilities, and the effectiveness of training stimuli and methods. Participants will complete cue-weighting perception experiments, sequence-recall experiments, visual-world eye-tracking experiments, and perceptual training experiments, as well as proficiency and perceptual aptitude tests.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.