Effects of regiolects on the perception of developmental foreign accent syndrome

Foreign accent syndrome (FAS) is a relatively rare speech motor disorder in which the pronunciation of an affected speaker is perceived as distinctly foreign by listeners of the same language community. Because of various close semiological resemblances with apraxia of speech, FAS has been hypothesized to be an apraxia subtype. In 2009 two cases of developmental FAS (dFAS) were described in whom the disorder was detected in an early stage of their speech-language development in the absence of brain damage or mental illness. In the present study, two listening panels consisting of 30 native speakers of two regiolects, Dutch and Flemish, evaluate the spontaneous speech of two native Flemish-speaking boys with suspected dFAS, three native Flemish-speaking children diagnosed with developmental apraxia of speech (dAoS), two bilingual children (L1 = Flemish, L2 = French or English), and six native Flemish-speaking children with typical speech-language development. Whereas the Dutch panellists were not able to distinguish the different groups, the Flemish listeners accurately identified the children with dFAS and the bilingual children. None of the listeners were able to discern between dFAS and dAoS. The latter finding supports the assumption that the two speech disorders not only share similar semiological and perceptual characteristics but also a common pathophysiological substrate. Although it is not always identified by listeners of the same language community but is by speakers of the same regiolect, in addition to FAS resulting from brain damage or a psychological disorder, dFAS appears a distinct form of apraxia of speech resulting from developmental deficits.