Auditory neural tracking and lexical processing of speech in noise: Masker type, spatial location, and language experience

Abstract

The present study investigated how single-talker and babble maskers affect auditory and lexical processing during native (L1) and non-native (L2) speech recognition. Electroencephalogram (EEG) recordings were made while L1 and L2 (Korean) English speakers listened to sentences in the presence of single-talker and babble maskers that were colocated or spatially separated from the target. The predictability of the sentences was manipulated to measure lexical-semantic processing (N400), and selective auditory processing of the target was assessed using neural tracking measures. The results demonstrate that intelligible single-talker maskers cause listeners to attend more to the semantic content of the targets (i.e., greater context-related N400 changes) than when targets are in babble, and that listeners track the acoustics of the target less accurately with single-talker maskers. L1 and L2 listeners both modulated their processing in this way, although L2 listeners had more difficulty with the materials overall (i.e., lower behavioral accuracy, less context-related N400 variation, more listening effort). The results demonstrate that auditory and lexical processing can be simultaneously assessed within a naturalistic speech listening task, and listeners can adjust lexical processing to more strongly track the meaning of a sentence in order to help ignore competing lexical content.