On the nature of the foreign accent syndrome: a case study.

A detailed acoustic analysis was conducted of the speech production of a single patient presenting with the foreign accent syndrome subsequent to a left-hemisphere stroke in the subcortical white matter of the pre-rolandic and post-rolandic gyri at the level of the body of the lateral ventricle. It was the object of this research to determine those changes which contribute to the perception of a "foreign accent." A number of acoustic parameters were investigated, including features of consonant production relating to voice, place, and manner of articulation, vowel production relating to vowel quality and duration, and speech melody relating to fundamental frequency. The results indicated that many attributes which might have contributed to the foreign quality of the patient's speech were similar to those of normal English speakers. However, a number of critical elements involving consonant and vowel production and intonation were impaired. It was hypothesized that the acoustically anomalous features are linked to a common underlying deficit relating to speech prosody. It is suggested that the normal listener categorizes this speech pattern as a foreign accent because the anomalous speech characteristics, while not a part of the English phonetic inventory, reflect stereotypical features which are a part of the universal phonetic properties found in natural language.