A case of foreign accent syndrome: Acoustic analyses and an empirical test of accent perception

Foreign Accent Syndrome (FAS) is a rare acquired syndrome following stroke, manifesting as a perceived change in the speaker’s accent. We present acoustic-phonetic analyses of the speech of a patient, RD, with FAS presenting as an apparent accent shift from Southern Ontarian to Atlantic Canadian who was first described in Naidoo, Warriner, Oczkowski, Sévigny, and Humphreys (2008). As well as more fully documenting this case, this paper also seeks to examine whether the accompanying articulatory deficits constitute a mild form of some other motor speech disorder such as apraxia of speech (AOS) or dysarthria. Acoustic-phonetic analyses showed increased vowel formant variability, overlap of voice onset times for phonemically contrastive stops, inconsistent consonant distortions, and global prosodic attenuation. These, combined with the patient’s fluent speech, can account for the perception of a foreign accent as opposed to disordered speech. The observed inconsistency of consonant distortions coupled with other articulatory deficits suggest that at least in this case, FAS can be considered to be a mild form of AOS.