Influence of mothers' slower speech on their children's speech rate.

This study investigated the effects on children's speech rate when their mothers talked more slowly. Six mothers and their normally speaking 3-year-olds (3 girls and 3 boys) were studied using single-subject A-B-A-B designs. Conversational speech rates of mothers were reduced by approximately half in the experimental (B) conditions. Five of the six children appeared to reduce their speech rates when their mothers spoke more slowly. This was confirmed by paired t tests (p < .05) that showed significant decreases in the 5 children's speech rate over the two B conditions. These findings suggest that when mothers substantially decrease their speech rates in a controlled situation, their children also decrease their speech rates. Clinical implications are discussed.

Disfluency and time perception.

Stuttering is manifested as a disruption in speech timing, but it may stem from a more basic temporal disorder (R. D. Kent, 1984). We compared the ability of stuttering and nonstuttering adults to estimate protensity and to distinguish the relative lengths of short tones. We also examined whether there is a correlation between a person's degree of disfluency and the ability to measure protensity or judge the relative lengths of short tones. Twenty stuttering and 20 nonstuttering adults were given the Duration Pattern Sequence Test. They were also asked to estimate the lengths of 8 tones and silent intervals. A negative correlation was found between degree of disfluency and ability to determine the relative lengths of short tones. A positive correlation was found between degree of disfluency and length of protensity estimates.

Parent verbal interactions and speech rate: a case study in stuttering.

This single-case study of indirect stuttering treatment is intended to identify variables for further research. The study used post hoc analyses of changes in parent speech variables and changes in the child's stuttering. The analysis was conducted in two parts. Study I examined the relationships between the child's percent syllables stuttered and the parents' speech rates and percentages of nonaccepting statements, interruptions, questions, nonaccepting questions, and talk time. The only parent variable significantly correlated with the child's stuttering was the mother's speech rate. In Study II the child's percent syllables stuttered were subdivided into primary (effortless) and secondary (tense) stuttering. Each category was then correlated with the parent variables examined previously. Results suggested that the parent variables that were significantly related to the child's primary stuttering were not the same as those significantly related to her secondary stuttering. Specific parent variables are suggested for further study.

Onset sequencing of selected lip muscles in stutterers and nonstutterers.

The present study examined lip muscle activity during the speech production of stutterers and fluent speakers to provide information about the nature of stuttering blocks. Depressor Anguli Oris (DAO) and Depressor Labii Inferioris (DLI) were recorded, using hooked-wire electromyography (EMG), in 3 stutterers and 3 nonstutterers during productions of the words "peek", "puck", and "pack." EMG records indicated that nonstutterers activated DAO prior to DLI for production of the initial/p/. Stutterers frequently reversed this sequence of onset, particularly when they stuttered. Results are discussed in terms of mistiming versus anticipatory hypertension hypotheses about stuttering.

A comparison of stutterers and nonstutterers on masking level differences and synthetic sentence identification tasks.

Ten stutterers and ten nonstutterers, matched for sex, were tested for Masking Level Differences (MLDs) at 500 Hz, and were evaluated on the Synthetic Sentence Identification test with Ipsilateral Competing Message (SSI-ICM) under message-to-competition ratios (MCRs) of 0, -10, and -20 dB. No significant differences on the SSI-ICM task were seen between groups, but the stutterers did produce significantly (p less than .01) poorer MLDs than the nonstutterers. This may be interpreted as support for Kent's (1983) hypothesis that stutterers may be poorer at temporal processing. In addition, the present results support the concept of a continuum of auditory processing ability, with normals and stutterers of different degrees of disfluency revealing decreasing performance measures.

Reliability of verbal-manual interference.

Considerable recent research has used unimanual finger tapping with concurrent vocalization to assess hemispheric lateralization for language. This study examined whether an index finger tapping task is a reliable measure in adults and whether the task demonstrates sex differences in hemispheric specialization for language. Thirty right-handed subjects, fifteen male and fifteen female, between the ages of 18 and 25 were tested. The task measured the differences in tapping rate for each hand between tapping with and without a concurrent verbal task. The task was completed once each day for 3 consecutive days to determine reliability. The tapping task was found to be a reliable measure. No significant differences were found between tapping scores of males and females.

Control of upper airway structures during nonspeech tasks in normal and cerebral-palsied subjects: EMG findings.

Electromyographic (EMG) recordings taken from 13 orofacial and mandibular muscles during a sequence of nonspeech movements were compared in six normal and six cerebral-palsied adult subjects. Abnormalities in the amplitude of muscle activity and timing of muscle control in the cerebral-palsied subjects were borne out in statistically significant differences between the two subject groups on five measures of muscle activity. The findings do not support hypotheses that weakness affects individual upper airway muscles in cerebral-palsied persons or that a pathological imbalance between positive and negative oral reactions is present in these subjects. A possible mechanism for hypertonicity in facial muscles in cerebral palsy is suggested, based on inappropriate activation patterns across muscles. The results are consistent with a previous proposal that a defect in the specification of motor commands and/or their communication to muscles is a fundamental abnormality in cerebral-palsied individuals which affects both speech and nonspeech motor control.

Stuttering: speech pattern characteristics under fluency-inducing conditions.

Speech samples were collected from three adult male stutterers under six baseline conditions and 15 conditions believed to increase fluency. After moments of stuttering and filled pauses had been deleted from the samples, a speech pause analysis technique developed by Goldman-Eisler was used to measure the following speech pattern characteristics: mean phonation duration (i.e., the duration between pauses), pause proportion, articulation rate, fluent speech rate, mean sentence length, and percentage of syllables stuttered. Greater than 50% reduction in stuttering occurred in all but three conditions (Speak and Write, Relaxed, Alone with cards). Greater than 90% reduction occurred under Prolonged/DAF speech, Singing, Chorus reading, Shadowing, Slowing, Syllable-timed speech, and Response contingent stimulation. The data were examined for evidence of speech pattern characteristic changes which were associated with reduced stuttering. Lengthened mean phonation duration occurred consistently under four conditions: Chorus reading, Shadowing, Singing, and Prolonged/DAF. Slowed speech (lower overall rate, lower articulation rate, or increased pause proportion) occurred consistently in seven conditions: Prolonged/DAF, Slowing, Syllable-timed speech, Arm swing, Speak and write, Relaxed, and Singing. Only in Prolonged/DAF speech did lengthened phonation duration occur in conjunction with slowed speech. The results of this exploratory study suggest that stuttering may be reduced under different conditions by means of different strategies. Lengthened phonation and slowing were the predominant strategies used in those conditions investigated in this study. The results are consistent with those of effective treatment techniques. Theoretical accounts of the association between change in fluency and change speech pattern characteristics are discussed.

Procedures for verification of electrode placement in EMG studies of orofacial and mandibular muscles.

Many muscles used in speech are small and intimately interconnected. There is a need for anatomical and physiological data which would allow identification of the particular muscle fibers being recorded in electromyographic (EMG) investigations. EMG recordings were taken from eighteen orofacial and mandibular muscles while gestures believed to be specific to each muscle were performed. The anatomic criteria for the placement of the electrodes, the quality of the EMG spikes and interference patterns obtained, and the degree of differentiation of the temporal sequence of activity from that in neighboring muscles were used to decide on the degree of certainty that a particular muscle was being recorded. The appropriateness of each gesture as a stimulus to any muscle was determined on the basis of the level of activation occurring with the gesture relative to other muscles and its degree of variability between subjects.

The attribution of personality traits: the stutterer and nonstutterer.

Three videotaped recordings were made of an adult male speaking in an interview situation. Tapes differed as a function of the fluency exhibited by the interviewed speaker (i.e., fluent speech, primary stuttering, secondary stuttering). Three audiotapes were recorded from the videotapes yielding six stimulus tapes. Independent groups of college students saw and/or heard one of the stimulus tapes, each described as an interview with a "male who stutters." The fluent audio- and videotapes were replayed to two additional groups but were described only as an interview with a "male." Groups rated the personality of the speaker after tape presentation. Results revealed no difference in personality trait assignment as a function of experimental variables. However, in a second experiment two groups of college students rated a hypothetical normal speaker and hypothetical stutterer as significantly different in personality attributes. Results are discussed with reference to stereotyping behavior.

Meta-analysis of the effects of stuttering treatment.

Despite the many reports of stuttering treatment, there is little consensus either on the long term effectiveness of treatment or on which treatments are the most effective. The literature was searched for treatment outcome studies that reported sufficient data to allow a meta-analysis to be conducted. Forty-two studies covering the treatment of a total of 756 stutterers were located. In these studies the typical client was a 25-year-old severe stutterer who received 80 hours of symptom reduction treatment. Most studies used reliable measures of both stuttering and attitude to assess improvement some six months after treatment had ended. Treatment effects were calculated from 116 pre- and posttreatment pairs of measures. Average effect size was 1.3, which indicates that after treatment the groups of stutterers experienced a 1.3 standard deviation improvement in their pretreatment scores. Clearly, stuttering treatments can be beneficial, and the benefits appear comparable to other treatments in the health sciences. Prolonged speech and gentle onset techniques evidenced better gains in the short term and long term than either attitude or airflow techniques. These four seem preferable to any of the other reported treatments and were certainly better than no treatment.

Tonic stretch reflexes in lip, tongue and jaw muscles.

Despite considerable speculation it remains unclear as to whether stretch reflexes perform a functional role in speech articulator muscles. Recent research, however, has shown that long loop stretch reflex mechanisms are brought into play during voluntary contraction of limb muscles and a functional role in oscillatory damping has been suggested. It was decided, therefore, to use a method and a technique of analysis similar to that used in limb muscles to search for tonic stretch reflex (TSR) responses in lip, tongue and jaw muscles during sustained voluntary contraction. The term 'action TSR' is used to differentiate stretch reflex responses measured from voluntary activity from those measured at rest. Simultaneous electromyogram (EMG) recordings were taken from the lip, tongue and jaw musculature in normal, stutterer and cerebral spastic subjects. Subjects were instructed to hold the appropriate articulator in a fixed position while the experiment applied an irregular, continuously changing, stretching force. The stretch and EMG signals were analyzed using a cross correlation and spectral analysis technique. This provided a sensitive means of detecting any EMG fluctuations which covaried with applied stretch and might therefore be classified as reflex. No suggestion of such action TSR responses could be found in lip or tongue muscles of any of the subjects tested, including the cerebral spastic subjects with dysarthric speech. It is therefore concluded that action TSR mechanisms are not operative in control of lip and tongue muscles in man. Furthermore, dysarthric speech in cerebral spasticity cannot be attributed to exaggerated tone of lip and tongue muscles resulting from hypersensitivity of TSR mechanisms. In contrast, clear action TSR responses were demonstrable in jaw closing muscles while in jaw opening muscles, small amplitude responses were detected but were not substantial in comparison with background activity. Since the action TSR is present in jaw and limb muscles, but absent in lip and tongue muscles, the suggestion of a functional role of this reflex in damping mechanical oscillations associated with inertial loads is further supported.

Speech clinicians' attribution of personality traits as a function of stuttering severity.

Thirty-six speech-language pathologists participated in a study to evaluate clinicians' preconceptions of persons who stutter. Each rated a designated construct (the normally fluent individual, the mild stutterer, the moderate stutterer, the severe stutterer) using a personality trait scale. Results indicated that clinicians stereotypically assign negative personality traits to all levels of stuttering severity relative to normal. Their ratings further demonstrated that stutterers are generally considered to be a homogenous group. Differentiation amongst stutterers was made only between the polar ends of the stuttering severity continuum (that is, mild vs. severe). Clinicians' sterotypical trait assignment was not related to their professional experience. Results are discussed with reference to their clinical implications.

Stuttering therapy: the relation between attitude change and long-term outcome.

Previous research has indicated that attitude change generally follows behavior change in operant stuttering therapy programs. This study sought to examine the longterm therapy outcome of stutterers whose communication attitudes were not substantially normalized after fluency establishment and generalization. Posttransfer attitude scores of 20 stutterers were used to classify them into one of two groups: those whose communication attitudes had been modified to show less abnormality than the mean level for normal speakers, and those whose attitudes had not. Follow-up interviews with the 20 stutterers one year later indicated that those whose posttransfer attitudes were not substantially normalized stuttered significantly more. Theoretical and clinical implications are discussed.

EMG feedback and recovery of facial and speech gestures following neural anastomosis.

A case report is presented of an attempt to increase muscle activity during nonspeech and speech activities through surface electromyographic feedback. The subject, a 25-year-old male, had a surgical anastomosis of the seventh cranial to the twelfth cranial nerve five years prior to the initiation of this therapy. The right side of the face was immobile. Frequency analogs of muscle action potentials from the right lower lip during pressing, retraction, eversion, and speech were presented to the subject. His task was to increase the frequency of the tone thereby increasing muscle activity. The subject made substantial improvement in the gestures listed above. Electrodes also were placed in various infraorbital positions for an upper lip lifting task. This gesture was unimproved. Pre- and posttherapy independence of facial gestures from conscious tongue contraction was found. Possible explanations were proposed for (1) increases of muscle activity in the lower lip, (2) lack of change of MAPs in the upper lip, (3) independence of the facial muscle activity from conscious tongue contraction, and (4) effectiveness of this feedback training.

Pretreatment factors associated with the outcome of stuttering therapy.

Measures of stuttering behavior, personality, and attitudes about speaking were obtained from 20 stutterers at the beginning of treatment. These measures were correlated with three measures of stuttering behavior a year after treatment. Pretreatment attitudes were most highly related to outcome. followed by pretreatment stuttering behavior, and then personality measures. Multiple regression analyses of the pretreatment measures demonstrated that combinations of these variables correlated moderately high (r = 0.79, 0.66, 0.73) with outcome. Prediction equations derived from the multiple regression analyses were used to predict outcomes for an independent group of 18 stutterers. Predicted and actual outcomes were shown to be correlated moderately high (r = 0.75, 0.73, 0.51). Suggestions for clinical use of predictive factors are given. Implications for the design of treatment and understanding the nature of stuttering are discussed.

Reduction of stuttering frequency using analog electromyographic feedback.

Three stutterers were taught to reduce resting muscle activity by using analog electromyographic feedback from four sites over different muscle groups. They were then trained to reduce muscle activity prior to uttering selected sentences. A functional analysis was performed to determine the relationship between the decrease in stuttering frequency on initial phonemes and the reduction of electrical activity at each muscle site. Subjects demonstrated different responses to training. One subject's greatest decrease in stuttering frequency was associated with muscle activity training at a lip site. A second subject's greatest decrease in stuttering was associated with training at a laryngeal site. A third subject's greatest decreases in stuttering were with both lip and laryngeal site training. Following these demonstrations that stuttering could be controlled with electromyographic feedback, a practical management program was designed for a fourth stutterer. Feedback training to reduce electromyographic activity when paired with speech resulted in elimination of stuttering in two monitored situations, conversations and telephone calls. Probes indicated the stuttering continued to be markedly reduced in all situations nine months after treatment.