Changes in Aerodynamic Characteristics of Stutterers' Fluent Speech Associated with Therapy

Abstract

Stuttering frequency and four aerodynamic measures of articulatory events within perceptually fluent voiced and voiceless intervocalic intervals were obtained from 15 stutterers prior to and at the termination of a concentrated program of stuttering therapy. Three of the four aerodynamic variables showed group changes over the course of therapy concomitant with improvements in fluency. Additional correlational analyses suggested that one of the aerodynamic variables was specifically related to stuttering frequency. It is argued that both fluency enhancing and ancillary components of therapy operate to influence the intervocalic interval.

Orofacial Movements Associated With Fluent Speech in Persons Who Stutter

“…The differences in the direction of movement speeds for LPS and HPS, in conjunction with the elevated movement durations in the sentence productions of HPS, suggest that qualitatively distinct control processes were operating in the two groups during the production of fluent speech. Our tentative interpretation is that the fluent sentence productions of HPS were characterized by learned adaptive behaviors intended to enhance speech fluency, because reduced movement speeds and prolonged durations are characteristic of the speech of PS following some forms of therapy (McClean et al, 1990;Samar et al, 1986;Story et al, 1996). Reduced speeds and prolonged durations also would be consistent with reduced levels of muscle activity (McClean & Tasko, 2003) and decreased levels of reflex gain that might enhance speech fluency (Zimmermann, 1980b).…”

“…An alternative perspective on kinematic differences in speech between PS and NS is that they, in part, reflect processes specific to the speech motor system of PS that are intended to enhance speech fluency. Such processes are reflected in increased movement durations in the fluent speech of PS following some forms of speech therapy (McClean, Kroll, & Loftus, 1990;Samar, Metz, & Sacco, 1986;Story, Alfonso, & Harris, 1996). There is also modest evidence that more severe PS who have not undergone therapy tend to display increased movement durations and reduced velocities in their fluent speech (McClean, Kroll, & Loftus, 1991).…”

Stuttering

“…It is puzzling, therefore, that so little interest has been directed at finding their critical component(s) in order to improve the efficiency of treatment. In six before-and-after therapy evaluations of the speech of stutterers, treated by either Van Riper type therapy (Metz, Samar, & Sacco, 1983;Ramig, 1984;Samar, Metz, & Sacco, 1986) or prolonged speech programs (Mallard & Westbrook, 1985;Robb, Lybolt, & Price, 1985;Shenker & Finn, 1985), it appeared that durational components in certain acoustic and aerodynamic variables were changed by therapy. But the importance of these changes to the production of normal sounding speech was not identified; nor are they likely to be without controlled manipulations of these variables independent of therapy.…”

Modifying Electroglottograph-Identified Intervals of Phonation

“…There is also some evidence that when adults who stutter receive treatment based on prolonged speech, their posttreatment improved speech is characterized by increases in phonation time (Mallard & Westbrook, 1985;Robb, Lybolt, & Price, 1985). Similar effects have been found to occur with other types of treatment (Metz, Samar, & Sacco, 1983;Ramig, 1984;Samar, Metz, & Sacco, 1986). However, the relationship between changes in the duration of specific intervals of phonation and reductions in stuttering during fluency-inducing conditions has not been fully investigated.…”