Some acoustic aspects of fundamental frequency of CVC utterances in aphasia.

A set of 9 CVC utterances were elicited five times each from a group of 5 anterior and 7 posterior aphasics. These spoken tokens were acoustically analyzed for the fundamental frequency of phonation and compared to tokens for a group of 7 normal control speakers. Statistical analyses revealed that anterior aphasics produced significantly higher average fundamental frequencies than did normal speakers, and that both groups of aphasics had significantly greater variability (both inter- and intraspeaker) in their fundamental frequency values than did normal speakers. A subset of these data was also analyzed for the period-to-period variation or 'jitter' of the acoustic waveform. Each group was significantly different from each other: posterior aphasics demonstrated the greatest period-to-period variation followed by anterior aphasics and then normal subjects. Some implications of this research are discussed.