Date of Award
Master of Arts
Speech, Language and Hearing Sciences
Dr. Stephen M. Tasko
Dr. Helen M. Sharp
Dr. James Hillenbrand
Stuttering, formant, feedback, fluent, etiology
Masters Thesis-Open Access
A recent theory proposed by Civier and colleagues (Civer et al. 2010; Civer et al. 2013) developed a model of stuttering that implicates a faulty feedforward control system. The hypothesis suggests that stuttering results from relying too heavily on sensory feedback to guide speech movements. An overreliance on sensory feedback would result in subtle anomalies in fluent speech (such as slowed articulatory transitions) as well as overt stuttering behaviors (such as sound repetitions). The present study tested this general hypothesis by comparing articulatory transition rates of adults who do and do not stutter across casual and fast speech rates. Participants included 26 adults who stutter (AWS) and 28 normally fluent speakers (NFS) drawn from the Walter Reed-Western Michigan University Stuttering Database. Acoustic measures of articulatory transitions between the initial bilabial plosive /b/ and subsequent vowel /æ/ for the test utterance “a bad daba” (/ə bædæbə/). Acoustic data were analyzed for the following five measures 1) overall speech rate, 2) first and second formant transition durations, 3) first and second formant transition rates. For all measures, AWS tended to produce longer formant transition durations and slower transition rates compared to NFS, but the differences were not significant. The findings suggest that, there are some differences in formant values for AWS compared to NFS which are not significant. In general, findings from the current study do not provide strong support for the overreliance on feedback hypothesis.
Arnold, Kaitlin, "Formant Frequency Transitions in the Fluent Speech of Adults who do and do not Stutter: Testing the over-reliance on feedback hypothesis" (2015). Masters Theses. 590.