Lexical age of acquisition effects on native and non-native speech perception

Abstract

Lexical difficulty has been shown to play a role in both speech production and perception. The relative difficulty of a word can be determined based on lexicon properties such as usage frequency, neighborhood density, or lexical Age of Acquisition (AoA). These factors have been shown to predict a range of different acoustic modifications such as hyperarticulation and increased duration. The current study investigates the effect of AoA-conditioned phonetic variation in both plain and foreigner-directed speech conditions on both native and non-native English speech perception. 60 total subjects completed a lexical decision task. Investigating these two populations allows for an examination of the role of lexical difficulty in language acquisition. The data show that lexical AoA influences the accuracy of lexical decision responses. Specifically, native speakers were more accurate in their identification of words with a low AoA rating compared to a high AoA rating (i.e. more lexically difficult items). Interactions between AoA and speech condition were also observed. The findings of this study suggest acoustic modifications can serve, at least in part, to facilitate the perception of lexically difficult words.