Speech and Hearing Sciences ETDs

Publication Date



Purpose: The purpose of this study was to explore changes in disfluent speech during adaptation to better understand the mechanism for improving fluency in People Who Stutter (PWS). It was hypothesized that disfluencies would become less complex and shorter in duration with successive oral readings similar to changes noted in fluent speech. Method: This study included seven participants who stuttered. Digital sound and video recordings were used to acoustically analyze disfluent speech at both the reading and word level. Group analysis was conducted to find patterns of change for both adapting and nonadapting subjects. The following measures were analyzed: frequency of stuttered events, frequency of pause events, overall time, disfluent time, fluent time, pause time, average disfluency time, and average pause time. A more detailed word analysis was conducted to compare duration of disfluent and fluent phonemic segments within the word for adapting participants. Results: Four of the seven participants experienced adaptation. Group data revealed significant reductions in fluent speech and overall speech time when the first and fifth readings were compared. When readings other than the fifth reading were considered, significant reductions in most measures were achieved by the group. Word analysis showed significant reduction for disfluent segments for participant 11007. All other statistical word analysis was not significant. Variability of fluent and disfluent segments was measured using standard deviation. Higher variability was show for disfluent segments. Conclusion: Although some significant reduction in disfluency duration with successive readings of a passage does occur, small sample size and high variability between subjects makes it challenging to identify patterns of change. High variability for disfluent segments compared to fluent segments across all adapting subjects gives insight into instability associated with the moment of stuttering.

Degree Name

Speech-Language Pathology

Level of Degree


Department Name

Speech and Hearing Sciences

First Committee Member (Chair)

Dale, Philip

Second Committee Member

Arenas, Richard




stuttering, persons who stutter, pws, adaptation, acoustical analysis, duration

Document Type