Highly proficient L2 speakers still need to attend to a talker's mouth when processing L2 speech

Abstract

Adults attend to a talker’s mouth whenever confronted with challenging speech processing situations. We investigated whether L2 speakers also attend more to the mouth and whether their proficiency level modulates such attention. First, in Experiment 1, we presented native speakers of English and Spanish with videos of a talker speaking in their native and non-native language while measuring eye-gaze to the talker’s face. As predicted, participants attended more to the talker’s mouth in response to non-native than native speech. Then, Experiment 2 explored whether language proficiency affects attention to the talker’s eyes and mouth when perceiving non-native, second-language speech. Results indicated that non-native speakers attended more to the mouth than native speakers, regardless of their level of L2 expertise. These results not only confirm that attention to a talker’s mouth increases whenever speech-processing becomes more challenging, but crucially, they show that this is also true in highly competent L2 speakers.