Recognizing words across regional accents: the role of perceptual assimilation in lexical competition

Unfamiliar regional accents disrupt spoken word recognition by L2 and L1 learners and L1 adults, and confuse ASR and smart systems. Little is known, however, about which aspects of non-native accents hinder word recognition, or what processes are involved. We assessed how Australian English (AusE) listeners’ recognition of words in unfamiliar accents is affected by two types of cross-accent perceptual assimilation: 1) other-accent phones that constitute ‘deviant’ versions of the matching AusE phonemes (Category Goodness assimilation: CG); 2) phones that cross a native phonological boundary, i.e., assimilate to mismatching AusE phonemes (Category Shift: CS). Eyetracking (“visual world”) revealed the timecourse of lexical competition during online identification of words spoken in Jamaican (JaME: vowel differences from AusE) and Cockney English (CknE: consonant differences), while choosing among four printed choice words: target, onset and offset competitors, unrelated distracter. Recognition was slower, and both competitor types were considered more and longer for JaME and CknE than AusE pronunciations; these effects were stronger for CS than CG differences. We conclude that: 1) perceptual assimilation plays a key role in cross-accent word recognition; 2) lexical competition involves not only onsets but also later aspects of words; 3) vowel and consonant variations affect lexical competition similarly.