The effect of visual input on the differential diagnosis of dysarthria subtypes

By R.I. Zraick, L.L. Sikes, T.J. Hutton, and P.N. Davis

The purpose of this study was to compare two perceptual methods for the identification of dysarthria subtypes: auditory input only vs. auditory-plus-visual input.. Graduate student-clinicians (N = 14) concurrently enrolled in their first course on Neurogenic Speech Disorders participated. Group One (n = 7) listened to audiotaped dysarthric speech samples, and Group Two (n = 7) watched and listened to the same dysarthric speakers presented via videotape. Subjects in both groups identified the classic dysarthria subtype using features described by Darley, Aronson, and Brown (1975). Subjects in Group One (audio only) identified 30% of the speakers correctly on average (range = 19 - 38%), while subjects in Group Two (audio-plus-visual) identified 36% of the speakers correctly on average (range = 22 - 50%). There was no statistically significant difference between groups for the entire set of speakers, nor for any individual speaker type. Interjudge reliability was moderate for subjects in both groups. Intrajudge reliability was low for subjects in Group One (audio only) and moderate for subjects in Group Two (audio-plus-visual). Results of this study are discussed in regards to training student clinicians and others to validly and reliably identify dysarthria subtypes, and directions for further research are offered.