Collaborative research: Listening out for variation: An investigation of mono- and bidialectal listeners in the U.S.

Is knowing two dialects like knowing two languages? While research has shown that listeners typically find it easier to understand speakers of their own dialect, a large number of listeners have lifelong exposure to multiple dialects, making them receptively bidialectal. This collaborative project explores the behavioral responses (speed and accuracy in understanding speech) and neurophysiological responses (measuring brain activity when hearing speech) of bidialectal and monodialectal adults listening to different dialects. The project specifically studies how context impacts what bidialectal listeners do, testing the hypothesis that these listeners switch between a flexible, but less efficient strategy when they are unsure which dialect to expect, and a focused, more efficient strategy when a given dialect is expected. The project focuses on receptively bidialectal listeners who have long-term exposure to their local dialect as well as Mainstream US English. Participants are tested in both university and community settings using a mobile laboratory (the Brain Bus), expanding on the typical populations used in dialect processing research and increasing participation in neuroscience research.

Bidialectalism is a under-researched and under-theorized concept in linguistics. However, the effect that long-term exposure to dialectal variability has on listeners' cognitive representations and strategies has implications for understanding how listeners process variation in general, and for conceptions of bilingualism and monolingualism as involving different cognitive architectures. By combining behavioral and neurophysiological measures, and building on recent developments in using neuroscience measures in speech perception, the project provides foundational insights on the cognitive and neural bases of bidialectal communication. The project manipulates dialect expectations in two different ways (using visual cues to talker-identity in one experiment, and preceding sentence accent in another), and to different degrees (strong vs. weak vs. no dialect expectations), to examine how generalizable context effects are, and to better understand where listeners draw boundaries between dialects.

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.