ANALYSIS OF STUTTERING BEHAVIORS IN ADULT STUTTERING SPEAKERS: APPLICATION OF THE LIDCOMBE BEHAVIORAL DATA LANGUAGE TAXONOMY by

Stuttering is a complex behavioral disorder. Previously, vague and unreliable terminology for classifying stuttering behaviors has limited progress in delineating this intricate disorder. However, with the introduction of the Lidcombe Behavioral Data Language (LBDL) taxonomy, objective terminology has greatly improved reliability and the opportunity to examine stuttering behaviors across large populations, replicate previous research, and compare individuals across geographical regions. The purpose of the current study was to examine the distribution and characteristics of stuttering moments across a large sample of adult stuttering speakers to explore the possibility of subgroups or subtypes of stuttering. The notion of subtypes in stuttering has been discussed across a wide range of stuttering literature, and would have significant impact on the diagnosis, prognosis, treatment, and ultimately, prevention of stuttering. Archived speech samples from 95 individuals were used in the current study. A reading passage and conversational monologue were collected from each participant. Each speaking sample was analyzed and each stuttered moment was assigned one of the five core stuttering categories from the LBDL taxonomy. Results of the study indicated significant differences existed with respect to the relative distribution of stuttering among the subcategories of the LBDL across speaking tasks. A significant difference was also observed between the core stuttering categories during the reading task. The type of speaking task did not affect overall stuttering frequency. Regardless of speaking task, fixed posture-inaudible was the most frequently occurring type of stuttering moment in adult stuttering speakers. Means and standard deviations were reported for all stuttering frequencies across categories. A small subset of participants displayed stuttering behaviors as solely repeated movements or solely fixed postures. The results of the current study confirm the LBDL taxonomy is objective and reliable, and support the notion of subtypes in stuttering, specifically as a) predominantly repeated movements, b) predominantly fixed postures, and c) mixed type.