On July 15, 2024, Dr Alan C. L. Yu, the William Colvin Professor, Chair of the Department of Linguistics at the University of Chicago, gave a lecture titled “Effects of phonological (un)certainty on lexical activation” at the invitation of the Bilingual Cognition and Development Lab. This lecture, held in Room 307 of the Center for Linguistics and Applied Linguistics, was hosted by Dr Rendong Cai and attracted faculty and students both from within and outside the university.
Alan Yu first introduced the research background: Individuals rely on both acoustic-phonetic and lexical information to identify speech sounds, but the degree of reliance on these two types of cues varies significantly across individuals. However, explanations and sources of these individual differences remain under-explored. He therefore proposed two research questions: 1) What is the nature of the relationship between acoustic-phonetic cue reliance and lexical reliance? 2) If the relationship is a trait, what is the source of this trait? He designed two experiments to address these questions. Experiment 1 investigated individuals’ reliance on lexical and acoustic-phonetic cues during speech perception. The results showed a trading relationship between the use of lexical and acoustic-phonetic cues; the weaker the reliance on acoustic-phonetic cues, the stronger the lexical reliance. This pattern was not task-specific, but reflected a trait in individuals.. Specifically, lexical reliance was related to the consistency or certainty of using acoustic-phonetic cues in identifying speech categories (i.e., phonological certainty), but was less related to the gradience of speech category identification. Experiment 2 examined individuals’ word identification in noise, directly exploring the relationship between lexical effects and acoustic-phonetic cue use. The results indicated that individuals with lower phonological uncertainty tended to be less affected by phonological neighborhood density. However, the gradience of speech category identification was not related to lexical effects. These findings revealed that stronger lexical reliance is related to greater phonological uncertainty. This is a trait that possibly stems from individual differences in subcortical neural encoding of phonetic signals.
The talk provided a novel perspective on understanding individual differences in speech perception. It inspired a heated discussion on the related issues and future directions regarding the use of new individual difference measures in speech perception, and the implications of the fine-grained cue-trading interpretation for speech processing and sound change.
After the talk, Alan Yu and colleagues visited the lab, and discussed how to facilitate collaborative research.
