Perception of oral diadochokinetic performances in elderly adults

Twenty speech-language pathologists judged the adequacy of oral diadochokinetic performances by ten normal young adult speakers, ten normal geriatric speakers, and four dysarthric speakers (foils) for the purpose of investigating age-related changes in speech. Listeners rated each speaker according to 11 perceptual dimensions. Significant differences in ratings were found among the three subject groups for 10 of the 11 perceptual dimensions. The performances of elderly normal adult speakers were rated farther from the "normal" endpoint of a seven-point continuum than those of the young normal adults. The listeners also reported lesser degrees of confidence in their ratings of the geriatrics in comparison with both young adult and dysarthric groups. Perceptual characteristics associated with oral diadochokinetic performance appear to be altered with advanced age. Further analysis of clinicians' judgments suggest support for Ryan and Burk's (1974) proposal that the speech of aged adults may fall at the "mild end of a dysarthric continuum." Results emphasized the need for development of clinical standards of speech normality for the geriatric population.