Phases in speech encoding and foreign accent syndrome

This study used perceptual and acoustic analysis to profile the speech characteristics of a single case (SD) of foreign accent syndrome (FAS) and to investigate the effects of conceptual-semantic (imageability), lexical (word frequency), and post-lexical (word length) variables on word production. SD's speech errors were consistent with the reported characteristics of FAS, including vowel lengthening, word stress mis-assignment, consonant cluster lengthening, and consonantal distortion. The following factors contributed to susceptibility to phonetic errors in speech output: low imageability, low frequency when combined with high phonetic complexity, and increasing word length. SD displayed preserved auditory perceptual abilities and a capacity for fluent auditory-to-phonetic conversion in repetition of non-words. We propose that this case of FAS might be best characterised as a disruption to automatised speech control processes but with compensatory mechanisms in place that allow the speaker to maintain some degree of accuracy in speech output. (c) 2006 Elsevier Ltd. All rights reserved.