Vocal changes in stutterers and nonstutterers during monotoned speech

For years, reports have circulated that stutterers experience marked decrements in their stuttering when they speak or read in monotone. Wingate has suggested that the ameliorative effects of various novel speaking conditions on stuttering can be attributed to modifications in vocalization induced by such conditions. The present study was conducted to see whether this explanation would extend to monotoned speech as well. Ten teenage and adult stutterers and 10 normal speakers were tested in control and monotone reading conditions. Dependent measures were the frequencies of disfluency and stuttering, fundamental frequency, fundamental frequency standard deviation, vocal SPL, vocal SPL standard deviation, and fluent reading rate. Only within-group statistical comparisons were made, because members of the two groups could not be matched pairwise along critical vocal parameters. The major findings of this study indicated that across the two conditions, both groups significantly reduced their fundamental frequency, fundamental frequency standard deviation, vocal SPL and vocal SPL standard deviation. Only the stutterers exhibited a significant decrement in disfluency and stuttering. The normals did not evince enough disfluency in the control condition for a reduction to occur during monotoning. Neither group effected a reduction in fluent reading rates. These and other findings and interpretations are discussed relative to Wingate's modified vocalization hypothesis.     

Stuttering and fluency: Exclusive events or points on a continuum?

In recent years, several studies have been conducted in which the fluency of stutterers was compared with that of normal speakers. These investigations have been of two basic types, some involving objective measures of physiologic, aerodynamic, or acoustic features of the subjects' fluent speech signal, and others involving experiments performed in which listeners attempted to distinguish the fluency produced by stutterers from that generated by normal speakers. The body of literature pertaining to each of these two types of investigations is reviewed and interpreted. The interpretations offered are then developed in an effort to shed further light on both fluency and stuttering. Implications for further research, as well as for the evaluation, treatment, and post-therapy assessment of stutterers are drawn.     

Stuttering theory,research, and therapy: A five-year retrospective and look ahead

This article reviews events in stuttering theory, research, and therapy that have transpired during the past 5 years. After the retrospective review, current work in the area of stuttering is examined. This analysis of the past and present was conducted in an effort to give clearer direction to future efforts to understand the disorder, and to study and treat it more effectively.     

Learning from negative outcomes in stuttering therapy: I. Getting off on the wrong foot

Considering the long history of research into stuttering, it is surprising that so little time has been devoted to the study of factors that contribute to the success of therapy. Even less attention has been devoted to uncovering forces that promote poor treatment outcomes. In this article and the companion piece that follows it, an attempt has been made to delineate what may prove to be predictors of unsuccessful therapy. In this first of the two articles, the focus in on the identification of patient, extraclinical, and clinician variables that could act to negate progress during the establishment phase of treatment.     

A case report on the use of flooding in stuttering therapy

The last several years have seen the development and use of anxiety-reduction procedures in stuttering therapy. Among these types of methods, systematic desensitization and reciprocal inhibition have been employed almost exclusively. Emotional de-conditioning by means of flooding or implosive techniques has been attempted far less often. This article presents a case report on the utilization of the flooding tactic. Results are offered and discussed relative to the question of whether the elimination of anxiety is a realistic goal in therapy. The suggestion is offered that what many stutterers may really need to develop is the ability to generate fluency-enhancing behaviors in spite of the presence of heightened emotionality.     

Effects of simulated stuttering on listener recall

In an investigation of the effects of simulated stuttering on listener recall, a presentation was varied on two factors: degree of stuttering (mild or severe) and information value of stuttered words (low or high). A control presentation featuring non-stuttered speech also was prepared. Five groups of 16 subjects were randomly assigned to, and participated in, one of the five listening conditions. Then they completed a 20-item recall test. A one-way analysis of variance revealed sognificant differences among the five conditions. Two-way analysis of variance disclosed no main effects. However, a significant interaction showed that recall was lowest in the severe stuttering-high information condition. The results are discussed in terms of attention to critical information.     

Rate changes in the speech of stutterers after therapy

The fluent speaking rate of nine adult male stutterers was compared before and after stuttering intervention. The subjects, ranging in age from 18 to 37 yr (mean, 25 yr, 3 mo), exhibited mild to severe stuttering prior to treatment. The only rate reduction strategy taught to subjects during intervention was to slow the first phoneme or syllable of sentences spoken. In addition, however, subjects significantly reduced their overall rate as determined by measurements made of their fluent speech at the middle of sentences, as well as overall sentence durations (excepting the first word of utterances). The data from this investigation are interpreted relative to the facilitation/simplification hypothesis.     

Reading abilities of school-age stutterers

The reading abilities of 20 school-age stutterers and their matched normally fluent controls were assessed by means of the Woodcock Reading Mastery Tests. Results indicate that the reading abilities of school-age stutterers are not significantly different from those of school-age normals. Similarly, knowing whether a subject was classified as a stutterer or normally fluent speaker was of minimal assistance in predicting the subject's reading performance. These findings suggest that school-age stutterers' reading abilities are within normal limits. An individual stutterer, just like an individual normally fluent speaker, may exhibit “reading problems”; however, caution should be employed in extrapolating from one individual stutterer's reading performance to the reading abilities of all stutterers.     

Vocal changes in stutterers and nonstutterers during high- and low-pitched speech

This study was conducted to provide an indirect test of Wingate's “modified vocalization” hypothesis. In this formulation, the improved fluency that stutterers experience in various novel conditions is attributed to changes in the key correlates of stress, namely, fundamental frequency, vocal SPL, and rate.Normal speakers and stutterers read aloud in an habitual condition following instructions to read at higher- and lower-than-normal pitches. Objective measures were taken of subjects' fundamental frequency, fundamental frequency deviation, vocal SPL, and fluent reading rate. Disfluences were also counted. Findings showed that both stutterers and normals altered several features of voicing from the habitual to the two experimental conditions. Significant condition main effects emerged for fundamental frequency deviation, vocal SPL, fluent reading rate, and disfluency. The only meaningful between-group difference noted showed that the stutterers were more disfluent than the normals across all conditions. Results were interpreted as supporting Wingate's “modified vocalization” position and were discussed relative to how the vocal changes observed might act to promote fluency.     

Dichotic speech perception: A comparison between stuttering and nonstuttering children

A stop consonant-vowel dichotic listening task was administered to 90 right- handed boys, 30 in each age group of 5, 7, and 9 yr. Half in each group were stutterers, half nonstutterers. Two and a half times as many stutterers as nonstutterers were found to display either a left-ear advantage (LEA) or no ear advantage (NEA). This finding suggested a greater tendency on the part of stutterers, as opposed to nonstutterers, for reversed or bilateral representation of the auditory speech areas of the brain. In addition, both stutterers and nonstutterers displayed significant developmental increases in the number of times they were able to identify both dichotic speech stimuli, thereby supporting the hypothesis of an age-related increase in children's total information processing capacity. The results are discussed in terms of the differences between stutterers and nonstutterers with respect to the issues of motor representation, cognitive modes, and higher-order linguistic processes.     

Vowel duration in stutterers participating in precision fluency shaping

The purpose of this study was to determine the extent to which stutters manipulate vowel duration to achieve fluency after participating in Precision Fluency Shaping. Nine stutterers who read an all-voiced sentence fluently before and after therapy were selected for study. Wide-band spectrograms were made of the initial phrase of the sentences, and vowel durations were computed. Results indicated that extended vowel durations were characteristic of the fluency of stutterers posttherapy. The subject that had the highest rate of disfluency after therapy also had the shortest vowel durations. Clinical implications concerning the importance of speech rate during carryover practice are made.     

Nonspecific elements in therapy with stutterers

Currently, many different strategies are employed by respected professionals working in the area of therapy for persons who stutter. This phenomenon serves as a point of departure for reflections on the nonspecific elements involved in therapy. Drawing on the literature of holistic medicine and psychotherapy these elements are identified as follows: (1) active participation of the client in the therapy process; (2) role of self-management skills; (3) influence of client's expectations regarding treatment; (4) suggestion as a factor in therapy; and (5) the therapeutic relationship.     

Phonatory initiation,termination, and vocal frequency change reaction times of stutterers

Four types of voice reaction times were investigated for eight adult stutterers and eight control subjects using a vocal shadowing paradigm. These were voice initiation and termination reaction times (VIT and VTT, respectively) and voice frequency-shift intiation and termination reaction times (SIT and STT, respectively). Results indicated that the stutterers were slower in VIT, but were as fast as their control subjects in VTT, SIT, and STT. It was suggested that a laryngeal discoordination problem of stutterers lies primarily in the stage of adduction (turning on the voicing) rather than in the stage of abduction (turning off the voicing) or in finer frequency control at the larynx.     

Syntactic influences on stuttering in young child stutterers

This study examined the location and rate of stuttering in the spontaneous speech of nine young stutterers (4.0–6.6 yr) in relation to certain aspects of syntax. It was designed to answer the following questions: Is there more stuttering at clause onset (boundary) than at other points in the clause? Does the type of clause influence rate of stuttering? Is there more stuttering on complex than on simple sentences? The syntactic analysis defined 10 clause types (seven pertaining to complex sentences and three pertaining to simple sentences); clause boundaries (taking into account “filler” words occuring in such positions); and hierarchical constituent structure within sentences. Stuttering was found with significantly greater frequency at clause boundaries than at internal (nonboundary) positions of clauses. This was apparent for nine of the 10 clause types, the exception being complement clauses. The word “and” at the beginning of simple and complex sentences provoked a high rate of stuttering. The hierarchical structure within the clause did not influence the location of stuttering, and sentence complexity was not a factor in the rate of stuttering.     

The effects of pacing and masking on stutterers' and nonstutterers' speech initiation times

The present study was undertaken to determine whether pacing and masking would facilitate improved speech initiation times (SITs) both for stutterers and for nonstutterers. All subjects were tested in control, pacing, and masking conditions. The results showed that both stutterers and nonstutterers (1) improved their SITs during the pacing condition as compared with the control condition (p = 0.01), (2) had slower SITs in the masking condition as compared with the control condition (p = 0.05), and (3) had faster SITs during the pacing as compared with the masking condition (p = 0.01). The SIT between-group findings demonstrated that stutterers were slower than nonstutterers across all SIT conditions (p = 0.08). The discussion of these results centers on the facilatory nature of novel stimulation in modifying speech-system functioning.