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.     

Stutterers' voice initiation times during conditions of novel stimulation

The present experiment examined stutterers' voice initiation times (VITs) during conditions of novel stimulation. The experimenters were interested in determining how VITs varied as a function of pacing and masking. Stutterers were examined in control, pacing, and masking conditions. The results indicated that: (1) stutterers significantly improved their VITs in the pacing condition as compared with the control condition (p = 0.005), (2) stutterers had significantly faster VITs in the pacing condition as compared with the masking condition (p = 0.005), and (3) stutterers improved VITs in the masking condition as compared with the control condition (p = 0.075). These results are discussed in terms of the facilatory nature of novel stimulation in modifying speech-system functioning.     

Some correlates of stuttering severity judgments

Thirteen adult male stutterers recorded the Amplifier Passage on high-quality audiotape. One sentence from each recording was paired with one sentence from each of the remaining 12 recordings. The resulting 78 sentence pairs were presented to eight speech-language pathologists who were asked to judge which stutterer in each pair was more severe and to rate the confidence of each of these judgements. The confidence ratings were analyzed by means of the individual differences model of multidimensional scaling. The results suggested that reading rate and the number of intrasentence pauses were important parameters in determining the severity of stuttering.     

Update: School-age stutterers

Field-test data is reported on 48 school-age stutterers evaluated with the Assessment of Fluency in School-Age Children during the 1980–1981 school year in East-Central Ohio, which is largely rural in character with small industrial cities. The data answers questions proposed in 1977 regarding issues relating to the identification of young stutterers, their awareness of disfluent speech, and management problems in a school setting.     

A test of the distraction explanation of disfluency modification in stuttering

The distraction explanation of changes in stuttering rate was examined in the present experiment. Twelve stutterers were compared with 12 nonstutterers who were matched for age, sex, and level of education. Subjects were tested for disfluency production under conditions designed to reflect the dimension of distraction. These conditions were: (a) over attention to speech (counting speaking errors). (b) “normal” conditions (no additional task), and (c) distraction (pursuit tracking of an irregular target). The results showed no effect on stuttering rate that could be attributed to the distraction conditions. However, stutterers rated the difficulty of these conditions in concordance with the distraction theory. It was suggested that, while stutterers' perceptions may account for the popularity of the distraction explanation, evidence supporting the theory is lacking.     

Rate reduction strategies used by normally fluent and stuttering children and adults

Speech rate can be reduced by prolonging the duration of phonetic units, by pausing between words, or through a combination of these approaches. Child and adult normally fluent speakers and stutterers were tested in basal and modified speaking rate conditions. Subjects' utterances in both conditions were converted to spectrographic displays so that measures of phonetic and pause durations could be made. Comparisons of these measures across conditions revealed that all four groups of subjects spontaneously extended pause and phonetic durations, the former more than the latter, when instructed to voluntarily reduce speech rate.     

Outcome predictors in the behavioral treatment of stuttering

The MMPI and subscales of the Stuttering Severity scale were utilized to predict motivation and success in the behavioral treatment of 32 stutterers. Subjects spent a mean of 10 individual sessions in criterion-oriented learning of fluent speech based on speech-muscle relaxation aided by EMG visual biofeedback. Judged motivation and judged success were strongly related to each other and significantly related to MMPI K and Es scores and negatively to F and Sc. Actual success was negatively related to Sc and Pd, completely unrelated to Es, and (if anything) negatively related to K. Results are consistent with previous studies, and show that global judgements of progress were only minimally related to a measure of actual progress.     

Variability in the initiation of articulatory movements in the speech of stutterers and normal speakers

This study was designed to investigate the differences between stutterers and normal speakers in phonatory and articulatory timing during the initiation of fluent utterances of monosyllabic words. Electromyographic recordings of four articulatory muscles and recordings of glottal vibrations were made of repetitive utterances of a series of monosyllabic words by 15 stutterers and 17 nonstutterers. These data were analyzed in terms of average interval times between voice onset and onset of EMG activity and between onset of EMG activity in each articulator and in terms of the intrasubject variability of these durational measures. Results showed that there were no significant differences between stutterers and nonstutterers in average interval times and that stutterers, in general, were significantly more variable in their speech onset timing. Findings are discussed in terms of recent hypotheses concerning the role of timing disturbances as the main source of speech disruption in stutterers.     

Patterns of regional cerebral blood flow during attempted reading aloud by stutterers both on and off haloperidol medication: Evidence for inadequate left frontal activation during stuttering

Two stutterers, both recent college graduates, were subjected to regional cerebral blood flow measurements while attempting to read aloud. Each one received two measurements, one of which was under the influence of haloperidol, 3 mg daily. Both subjects showed improvement on medication, allowing a stuttering versus essentially no stuttering comparisons for each subject. Both subjects showed higher Broca's area flow in the right compared to the left hemisphere, during stuttering. Both showed higher Wernicke's area flow in the left compared to the right hemisphere, however, during stuttering. During reading aloud without stuttering, however, the Brocas's area flows were reversed, now showing a left hemisphere advantage. The results were interpreted as consistent with H. M. Sussman and P. F. MacNeilage's (1975, Neuropsychologia, 13, 19–26) proposal that stutterers exhibit conventional left cerebral dominance for speech reception, but inadequate left cerebral dominance for speech production.     

Performance differences between stuttering and nonstuttering subjects on a sound fusion task

This study investigated the possibility that there are central auditory level processing differences between stutterers and nonstutterers. The experimental subjects were eight male and three female stutterers ranging in age from 20–45 yr, with a mean age of 31.2 yr. The control group consisted of the same number of males and females, ranging in age from 20–45 yr, with a mean age of 30.1 yr. Each subject participated in a sound fusion task under three variable conditions: 1) group performance (nonstutterers vs. stutterers); 2) ears (right vs. left); and 3) lead-time presentation (0–100 msec). Statistically significant differences were found for lead-time presentation.     

The speech production abilities of stutterers: Recent, ongoing, and future research

Recent and ongoing research into the speech production abilities of stutterers has followed four disparate paths. First, there have been objective studies of physiologic, aerodynamic, and acoustic parameters of stutterers' habitual speech patterns and the patterns they display while speaking in the presence of such novel stimuli as DAF or masking. Second, investigators have undertaken the fiberoptic examination of stutterers' larynges during fluent and stuttered utterances. Third, there have been studies of the speed with which stutterers start and terminate voicing independent of the act of speaking. Finally, there have been investigations of possible perceptible differences between the fluency of stutterers and normal speakers. Each of these four types of research is examined. Tentative conclusions are drawn, and directions for future theorizing and experimentation are suggested.     

An evaluation of the effects of supplemental “fluency” training during maintenance

The voice onset time (VOT) of two groups of treated stutterers and a normal-speaking group was assessed by spectrographic analysis. Both groups of stutterers had significantly slower VOT than the normal speakers. The experimental group of stutterers was given 8 wk of “fluency” training designed to remediate characteristics of speech identified as related to “tenuous” fluency. The control group of stutterers received ongoing maintenance therapy. Posttreatment VOT was assessed. The experimental stuttering group had significantly decreased their VOT in the direction of the normal-speaking group, whereas the control group of stutterers had a greater VOT between pre- and posttreatment. The implication of these results for the maintenance of fluency are discussed.     

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.     

Some effects of the Edinburgh Masker on stuttering during oral reading and spontaneous speech

This study assessed the effect of a voice-activated masking unit, known as the Edinburgh Masker, on the speech of four stutterers during oral reading and spontaneous speech. The results show that one stutterer reduced stuttering almost completely whenever the masker was activated. Two subjects showed either marginal or temporary reductions of stuttering during one speaking condition but showed no change in the other condition. The other subject reduced stuttering only during spontaneous speech. No reduction in stuttering was associated with reduced speech rate. A perceptual analysis procedure conducted to assess for altered speech quality during masking conditions found changes in speech quality were evident in two subjects. The clinical implications of these findings are discussed.     

Electroencephalographic and dichotic indices of cerebral laterality in stutterers

To test the hypothesis that stuttering is the product of faulty cerebral laterality four experiments were performed on each of five adult stutterers and five fluent speakers. These tests were: (1) dichotic listening with consonant-vowel pairs, (2) alpha recording over both hemispheres during the performance of cognitive tasks intended to engage preferentially the left or right hemispheres, (3) contingent negative variation with either an articulatory or bilaterally symmetrical response, and (4) readiness potential with the same responses. The results fail to disconfirm the null hypothesis regarding stutterers and their fluent peers. All subjects showed consistent patterns of cerebral laterality indicative of localization of speech function in the left hemisphere. Suggestions are made regarding a possible contribution of deficient sensorimotor integration in stuttering.     

Clinician attitudes toward stuttering: A decade of change (1973–1983)

The attitudes of 674 speech-language pathologists toward stuttering, stutterers, stuttering therapy, parents of stutterers, and related issues were studied during the years 1973–1983. During that period, clinician attitudes were found to shift away from support of the John-sonian concepts, which suggest parental causality and dangers in early intervention. In addition, clinicians became less likely to perceive stutterers as possessing psychologic disorders and misperceptions of their problem and of their interpersonal relationships. However, a significant number of clinician's were found to continue to hold unsubstantiated beliefs regarding the personality of stutterers, their parents, and the efficacy of early intervention with very young stutterers. The results of the study were interpreted as suggesting the need to educate fluency specialists.     

Quantifiers and question answering in young children

Two hypotheses were tested about how young children answer questions with the quantifiers all and some: (a) that children use syntactic cues in determining which noun phrase is quantified, and (b) that children evaluate a some-statement as part of evaluating an all-statement. To test these hypotheses, the same group of 60 4- to 7-year-olds were asked four contrasting types of quantitative questions. The results indicated that children can use syntactic cues under some presentation conditions. However, there was no evidence for an asymmetry between the all-and some-questions. A model of how young children might answer quantitative questions was then considered.     

The role of overt activity in children's sentence production

Nursery schooler's abilityto associate pairs of toys was assessed under four experimental conditions: (1) control, (2) S manipulating the toys, (3) S generating a sentence, and (4) S generating a sentence while manipulating the toys. All three S-involvement conditions produced significantly better recognition performance than the control but contrary to initial predictions, the difference between the sentence-only and sentence-plus-manipulation conditions was not significant. In contrast to previous research, Ss in the sentence-only conditions had little difficulty producing sentences when asked. Of interest was the finding that the quality of sentence production was poorer in the sentence-plus-manipulation condition than in the sentence-only condition. Results are discussed in terms of the possible “conflict” produced when the child is required to engage in more than one overt activity simultaneously.     

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.     

The identification of stuttering: Can you look and tell

This investigation focussed on how observers identify stutterers. It was found that stutterers are identified most correctly under visual circumstances as compared to auditory and combined auditory-visual conditions. Therefore, the reduction of stuttering should include removal of noticeable, interfering, and unnecessary nonverbal behaviors, particularly mouth and nostril movements.