Degree Name

Master of Science (MS)

Semester of Degree Completion


Thesis Director

Carl W. Dell, Jr.

Thesis Committee Member

Rebecca M. Throneburg


This study investigated second formant transition extent and direction in disfluent speech samples recorded close to stuttering onset in preschool age children. Comparisons were made among subgroups of children known to persist in stuttering, those who recovered from stuttering, and normally fluent control subjects. Twenty-eight subjects, eight persistent stutterers, eight recovered subjects, and twelve normally fluent subjects participated. These children were enrolled in the longitudinal Stuttering Research Project at the University of Illinois at Urbana. The initial consonant to vowel transition in the second formant of the repeated portion of the part-word repetition was compared to the transition in the final production. Ten transitions were analyzed for each subject in the stuttering subgroups, and between one and three transitions were analyzed for each control subject. The transitions were judged to be: 1) absent, 2) present/different direction, 3) present/same direction/non-target frequency, or 4) present/same direction/target frequency. A significant main effect was found for the number of absent F2 transitions produced (F=12.15; df=2; p=.0002). Further analysis using a Tukey HSD multiple comparisons post-hoc test showed significant difference existed between the control and persistent groups, and the control and recovered groups.