Expecting a challenge: A behavioral and neurophysiological investigation of talker identity in cross-dialectal speech perception

Listeners use their knowledge about a talker to guide speech perception. In the present study,we manipulated both the familiarity and predictability of this talker-specific knowledge. Twenty-two listeners from western Pennsylvania completed an audio-visual lexical decision task whileEEG was recorded. Critically, listeners were introduced to the talkers beforehand, with shortvideos establishing the talker’s U.S. English accent identity: Mainstream, more similar to theparticipants themselves; Southern, a relatively less familiar variety; and Unpredictable, whichswitched between Mainstream and Southern accents. During the task, listeners watchedthese talkers produce tokens with accents that either aligned with or violated their accentidentity. Behaviorally, alignment between talker and token accent influenced performance onSouthern-accented tokens, while accuracy on Mainstream-accented tokens was nearly at ceilingregardless of talker accent identity. Neurally, accent familiarity had the largest effect pre-speech(in response to the visual presentation of the talker), while both predictability and familiarityimpacted processing of the speech signal itself. Overall, our results suggest that listeners useinformation about a talker’s accent, even when it is unfamiliar or unpredictable, to alter theirlistening strategies for more successful speech recognition.