The effect of talker intelligibility on adaptation to an unfamiliar accent

Listening effort, as indexed by task-evoked pupil response, increases as the intelligibility of second language (L2) speech decreases, and this processing cost is mitigated by experience with talkers of the same accent (Porretta and Tucker, 2019). Prior research has shown that listeners can adapt to unfamiliar L2-accented speech and generalize the adaptation to different L2-accented talkers with the same L1 (Bradlow and Bent, 2008). The current study investigates what type of L2-accented speech exposure (high or low intelligibility) best reduces later listening effort to a novel talker of the same accent. We hypothesize that exposure to highly intelligible L2 speech supports adaptation to the features of an accent because it allows listeners to map accented tokens to the talker’s intended lexical representations. Alternatively, adaptation to a less intelligible talker may require exposure to other low-intelligibility speech, which is characterized by features that deviate more significantly from L1 norms. To test this, participants were exposed to simple sentences spoken in English by either L1 talkers, highly intelligible L2 talkers, or less intelligible L2 talkers. At test, all participants listened to different sentences spoken by a previously unheard L2 talker while listening effort was measured via pupillometry. Data collection is ongoing.