Laterality differences in child stutterers: heterogeneity, severity levels, and statistical treatments.

The purpose of this study was to determine the relationship between stuttering severity and hemispheric dominance, as measured by a dichotic listening task. Subjects were 76 stutterers and 76 nonstutterers who were asked to respond to a series of dichotically presented synthetic syllables. Results revealed (a) a right ear preference for both stuttering and nonstuttering subjects; (b) right ear, no ear, and left ear preference subgroups among the stutterers; (c) differences in dichotic ear preferences for the 7- to 12-year-old stuttering and nonstuttering subjects; and (d) a relationship between stuttering severity and hemispheric dominance depending on the manner in which the data were analyzed. The discussion considers the earlier studies in the literature and reconsiders the idea of subgroups within the stuttering population. Also discussed is the use of certain statistical treatments and the need to determine the relationship between hemispheric dominance in stutterers and other variables.