Acoustic analysis of voice in dysarthria following stroke.

Although perceptual studies indicate the likelihood of voice disorders in persons with stroke, there have been few objective instrumental studies of voice dysfunction in dysarthria following stroke. This study reports automatic analysis of sustained vowel phonation for 61 speakers with stroke. The results show: (1) men with stroke and healthy elderly men exhibited an identical voice profile, and men with stroke had only one significantly larger noise parameter (SPI--soft phonation index) than young healthy men; and (2) women with stroke and healthy elderly women exhibited an identical voice profile, except that women with stroke exhibited a significantly higher SPI than healthy elderly women. Although there were no significant differences in smoothed pitch perturbation quotient (sPPQ) and SPI between healthy elderly women and healthy young women, women with stroke exhibited significantly larger sPPQ and SPI than healthy young women. It is suggested that studies on sub-groups of the stroke population that use a combination of perceptual and acoustic analyses will better illuminate the voice dysfunction in dysarthria following stroke.