Data on disfluencies in the speech of non-stuttering adults are relevant to several aspects of the assessment and treatment of adults who stutter. Currently, very few sources provide relevant data. In the existing literature on normally fluent speakers, there is no consistency in sample length or topic or in which types of disfluency are counted.…

Comparison of the formant frequencies of 15 adult stutterers' fluent and disfluent vowels and of stutterers' and nonstutterers' fluent vowels indicated that differences (between stutterers and nonstutterers) could be accounted for by differences in vocal tract dimensions. No differences were found between frequencies of fluent and disfluent vowels…

Evaluation of 10 stutterers and 10 nonstutterers (all adults) on masking level differences (MLD) and synthetic sentence identification tasks indicated that stutterers produced significantly poorer MLDs than nonstutterers. There were no significant differences on the synthetic sentence identification task. (Author/DB)

This study examined whether stuttering speakers (N=10) differed from fluent speakers in relations between the neural control systems for speech and life support. It concluded that in some stuttering speakers the relations between respiratory controllers are atypical, but that high participation by the high frequency oscillation-producing circuitry…

This study investigated whether neuromotor differences between adults who stutter (n=10) and gender- and age-matched non-stuttering adults (n=10) are not limited to the movements involved in speech production. Results revealed significant differences between groups on measures of lip and jaw closing (but not opening) movements during speech and in…

The study investigated the reaction times in the fluent speech utterances of 20 adult stutterers and 20 nonstutterers. Results indicated that reaction times for longer utterances and for utterances requiring minimal preparation were longer for stutterers than for nonstutterers, suggesting stutterers may have difficulty in motor programing of…

The study investigated cerebral organization for visual language processing with 14 adult stutterers. Results showed the right hemisphere was superior for analyzing the concrete words while the left hemisphere was responsible for processing the abstract items suggesting some form of linguistic competition between the two hemispheres of this…

The study compared five adult stutterers' and five adult nonstutterers' fluent speech patterns produced during one nonshadowed reading and two speech-shadowing conditions (immediate repetition of a heard message). Among results were that stutterers produced fewer speech production errors than nonstutterers during shadowing conditions. (Author/DB)

Fourteen individuals who stutter and 14 nonstuttering individuals were assessed for the magnitude of their eye blink responses to noise bursts as a measure of temperament. Eye blink response to the initial noise burst and the mean of 10 responses were significantly greater for the stuttering group. Additionally, the Nervous subscale of the…

Analysis of lip and jaw motion in 18 stutterers and 10 nonstutterers found that adult stutterers who had been through speech therapy showed significant increases in jaw movement duration and time to peak velocity of the upper lip, lower lip, and jaw. Results suggest that anomalies in stutterers' fluent speech may be the result of acquired…

This study attempted to empirically demonstrate the validity of a twofold classification of speech disfluency in adult stutterers. Instrumentation and procedures permitting reliable identification and coding of 9 disfluency behaviors were developed and applied to monologues of 180 adult stutterers. Factor analyses supported the two-factor…

Analysis of use of positron emission tomographic measurements of resting-state regional cerebral blood flow in 29 men, 10 of whom stuttered, did not support the idea that developmental stuttering is associated with abnormalities of blood flow at rest. Findings did suggest an essentially normal functional brain terrain with a small number of minor…

Electrodermal activity, peripheral blood flow, and heart rate were recorded from 19 adult stutterers and 19 normal speakers during performance of jaw movements. There were no differences between the two groups of speakers, suggesting that the stutterers did not have abnormally high levels of autonomic activation in speech. (Author/DB)

In this study, 102 adult stutterers were assessed on state and trait anxiety before, and on trait anxiety after, intensive behavioral treatment. Results showed that persons who stutter have significantly higher levels of fear (trait anxiety) in a demanding speech situation and also higher levels of chronic anxiety (trait anxiety) than matched…

The study with three adult stutterers evaluated the effects of instructions to rate and modify the naturalness of their speech and compared their self evaluations with evaluations of listeners. (Author/DB)