Neurophysiologic Patterns of Semantic Processing of Accented Speech

Abstract

Perceiving and comprehending speech depends on the intelligibility of the speech signal. Frequently, communication occurs with adverse listening conditions including background noise or reverberation which compromise the intelligibility of the speech signal. Studies focused on the effects of these extrinsic degrading factors on the perception of a message after it has been produced. Fewer studies, however, explored the effect of a non-native accent on speech perception and comprehension ( Anderson-Hsieh et al., 1992 ; Munro & Derwing, 1995 ; van Wijngaarden et al., 2002 ). This study determines the effects of speech from a non-native speaker of English on semantic processing as it occurs in speech perception. Individuals made judgements about semantically congruent or incongruent sentences spoken by native or non-native accented speakers while we assessed processing of semantic information using behavioral and neurophysiological (ERP) responses. Two groups of 12 individuals between 20 and 30 years of age participated in this study. The results revealed a later N400 in response to a non-native accent. N400 effect results indicated that, compared to a native accent, listening to non-native accent increases semantic processing difficulty, even with relevant semantic context. • Non-native accented speech (NNS) has the same effect as noise on the listener. • Lower N400 amplitude shows semantic processing difficulty in non-native speech. • Addition of relevant semantic context does not significantly aid processing.