Sequencing of vocational development stages: Further studies

This paper reports two studies which support the prediction derived from Hershenson's (Journal of Counseling Psychology, 1968, 15, 23–30) life-stage vocational development model that average scores on Self-differentiation (worker self-concept and motivation) would exceed those on Competence (work habits, skills, and interpersonal relations), which in turn would exceed those on Independence (appropriateness and crystallization of vocational goals). The first study involved ratings by project staff on an inner city, socially disadvantaged population, and the second study involved self-ratings by individuals who had changed occupations in midcareer. Findings are consistent with those reported by Hershenson and Langbauer (Journal of Counseling Psychology, 1973, 20, 519–521) on a population of deaf clients.     

The voice problems of stutterers: A practical approach from clinical experience

Voice disorders, which may be caused by the stuttering problem, have been noted in at least one-third of stutterers seen. Basically, stutterers have false speech images that normal speech is perfect and without natural dysfluencies (repetitions, pauses, etc.). Many stutterers also have erroneous vocal images of how they should or should not sound. Both images control speech and voice. Clinical experience indicates that vocal rehabilitation should be used in conjunction with speech therapy for many stutterers.     

Speech and bimanual hand organization in adult stutterers and nonstutterers

A multivariate approach was used to investigate the relationship between speech fluency and bimanual handwriting in right-handed male stutterers and nonstutterers. Handedness was determined by the Harris Test of Lateral Dominance. Subjects were required to write the numbers 1 through 12 simultaneously, as quickly as possible. Speech measures were derived from the Stuttering Severity Instrument and from a reading passage. Stutterers performed more poorly than nonstutterers on all speech measures. There were no differences in bimanual handwriting performance for the dominant hand. However, stutterers performed more poorly than nonstutterers in nondominant handwriting. There were no relationships between speech measures and bimanual handwriting for stutterers or nonstutterers. Some stutterers performed better on the handwriting task than did some nonstutterers. It is suggested that disorganization in interhemispheric integration functions may be a more fundamental problem in stuttering than is incomplete cerebral dominance.     

Stability of performances of individual stutterers on oral reading adaptation tasks

This study aimed to determine whether individual oral reading adaptation task performances are sufficiently reliable to be used as predictive indicators of improvement in stuttering behavior by testing the stability of individual stutterers' adaptation scores. Results demonstrated that all stutterers are not stable in their individual adaptation scores and therefore individual adaptation scores may be insufficiently reliable for predicting and classifying. Theoretical and clinical implications are discussed.     

A comparison of the Probe technique and conventional therapy for young stutterers

This study contrasted the gains made in speech theraphy by 39 stutterers, 15 of whom were treated by conventional methods and 24 by the Probe technique. It was found that the Probe technique yielded substantially greater gains in fluency than did the conventional method, having more influence on final performance than factors such as initial fluency, time since onset of stuttering, or the presence of other unacceptable behaviors.     

A correlational study of stutterers' adaptation and voice initiation times

The purpose of this study was to determine the strength of the relationship, if any, between stutterers' amount of improvement in controlling phonation (voice initiation time) and their amount of improvement in stuttering during adaptation.Thirteen adult stutterers were required to participate in an adaptation task and a voice initiation time (VIT) task. The major finding was a weak, positive correlation between subjects' adaptation and their VIT difference scores. The correlation obtained, though weak, was interpreted to be informative; namely that while there is quite probably a laryngeal component in stuttering, it does not stand alone. It seems likely that the complexities of stuttering will not be fully understood until experiments include a number of potential or known dimensions of the disorder.     

Rate reduction strategies used by stutterers and nonstutterers during high- and low-pitched speech

Groups of child and adult normal speakers and stutterers were tested in an habitual condition and in conditions where they were instructed to read aloud at pitches both higher than and lower than normal. Objective measures were made of subjects' fluent reading rate, and vowel and pause durations across conditions. Disfluencies were also counted. Findings revealed that all four subject groups reduced their frequency of disfluency from the habitual to both experimental conditions. These decrements in disfluency were attended by significant reductions in fluent reading rate. Spectrographic analyses revealed that most subjects, regardless of age and speaker characteristic, affected their rate reduction by extending both vowel and pause durations. These results are compatible with those obtained in recent studies and are discussed.     

Effects of right hemisphere damage in an adult stutterer

One thesis on stuttering states that stuttering results from hemispheric imbalance of language. Some authors have reported stutterers who ceased stuttering following unilateral neurosurgical procedures, thereby correcting this imbalance. The first case of a stutterer in whom a right hemisphere stroke subsequently developed is reported here. The effects of the stroke on his speech production are discussed.     

Duration of subsegments within the intervocalic interval in stutterers and nonstutterers

Intervocalic intervals (IVI) from the contextual fluent speech of 14 stutterers and controls were examined at one-quarter speed on simultaneously prepared spectrograms and intensity x time displays. Seven subsegments within the IVI were identified and their durations compared between the two groups. Stutterers were slower than controls in transitional subsegments, corresponding to movements of the tongue and larynx, but not in steady-state subsegments. The results are interpreted as suggesting that stutterers are not able to move their laryngeal and supralaryngeal structures as quickly as nonstutterers.     

Effects of stimulus ear presentation on the voice reaction time of adult stutterers and nonstutterers

The initial and optimum voice reaction times (VRT) to auditory stimuli presented separately to the left and right ears of ten adult stutterers and ten nonstutterers was investigated. Subjects initiated the neutral vowel sound /Λ/ in response to one hundred 4000 Hz tones of 2.5 sec in duration. The silent intervals between the tones varied randomly. The stimulus cues were divided into five equal response sets of 20 tones each with 10 tones in each set being presented to the right ear and 10 tones to the left ear alternating back and forth. No significant differences were reported between the VRTs for cues presented to the left or right ears for either group. However, the stutterers exhibited voice reaction times which were significantly longer and more variable than those of the nonstutterers. The between- group differences were observed for what appeared to be the “optimum” level of voice initiation for the experimental task. These results lend to the speculative hypothesis that the observed difficulty for adult stutterers to promptly and consistently initiate vocalization may in part be attributable to inherent rather than learned factors.     

Vibrotactile magnitude production scaling: A method for studying sensory-perceptual responses of stutterers and fluent speakers

The method of vibrotactile mangitude production scaling was used to determine the tactile sensory-perceptual integrity for the dorsum of the tongue and thenar eminence of the right hand for 10 fluent speakers and 10 stutterers. It was discovered that both groups performed the task in a similar manner for the thenar eminence of the hand (a nonoral structure) but in a dissimilar manner for the tongue (an oral structure). From these data, it is suggested that the stutterers may maintain a different internal sensory-perceptual process for the tactile system involved in the speech process. The possibility exists that stuttering, for some, may be an “internal disorder” of the tactile-proprioceptive feedback mechanism that is directly involved in speech production.     

Decreases in simple reaction time as a function of stutterers'' participation in a behavioral therapy

Stutterers and fluent speakers were compared on a simple reastion time task to determine whether participation in a behaviorally based stuttering program had an effect on clients' reaction time scores. A group of fluent speakers was used to control the possibility that any changes in reaction time latency were due to practice or familiarity with the task. All participants responded with a finger-lift as quickly as possible to 25 visual stimuli presented by computer. Response latencies from the stutterers and the fluent speakers were compared. Stutterers' posttherapy reaction time latencies were significantly shorter than their pretherapy latencies. It was also observed that stutterers' reaction time scores prior to therapy did not differ significantly from fluent speakers' scores. However, stutterers' posttherapy reaction time scores did differ significantly from fluent speakers' posttest scores. The results are discussed in terms of arousal, motivation, familiarity with the environment, conditioned inhibition, and two aspects of therapy.     

Auditory phonemic perception in dyslexia: Categorical identification and discrimination of stop consonants

The possibility that phonological confusions may underlie some difficulties in processing written language was investigated using four speech perception tasks. Twelve dyslexic and four normal-reading children identified and discriminated synthetic speech syllables which varied either in voice-onset time (signaling the feature of voicing) or direction of formant transitions (signaling place of articulation). Results indicate that, like normal-reading children and adults, dyslexic children perceive these sounds categorically. Discrimination of the stimuli was limited by their identifiability. It is suggested that linguistic disturbances at other stages of the grapheme to meaning transformation underlie misreading.     

Reaction time for voiced and whispered /a/ in stutterers and nonstutterers

Recent research reviewed in this article suggests that stutterers' inability to initiate phonation promptly could be a significant factor in the occurence of stuttering. Since stuttering is either completely absent or markedly reduced in frequency during whisper, the present study tested the hypothesis that stutterers do not significantly differ from nonstutterers in reaction time (RT) for the initiation of whispered/a/, whereas the two groups differ significantly in RT for the initiation of voiced /a/. Ten adult stutterers and an equal number of comparable nonstutterers produced prolonged versions of the vowel /a/ using voice and whisper in response to tone stimuli. The results showed that stutteres and nonstutterers did not differ in RT for either voiced or whispered /a/. The stutterers, however, exhibited significantly longer RT to produce voiced /a/ than whispered /a/.     

Cerebral lateralization of visual stimulus recognition in stutterers and fluent speakers

Cerebral lateralization of stutterers and nonstutterers was assessed in terms of choice reaction times to stimuli presented to either the left or right visual hemifield on letter recognition and figure recognition tasks. Reaction times on both tasks were determined before and after a behavioral speech therapy program. Stutterers demonstrated a significant reduction in mean reaction times in the letter recognition task over the course of the therapy program. This change differed significantly from that obtained from stutterers in the figure recognition task. The stutterers' responses were in contrast to the responses of the nonstutterers, who showed no reduction in mean reaction times for the letter or figure recognition tasks. The results were discussed in terms of alterations in aspects of central nervous system processing as a result of participation in the behavioral speech therapy.     

Reaction-time measures of stutterers and nonstutterers

Ten adult male stutterers and ten adult male nonstutterers participated in six reaction-time tasks designed to measure manual, acoustic, and laryngeal-region response latencies. The analysis revealed statistically significant differences between the groups for the acoustic data only. The results indicated that acoustic reaction-time differences are not accounted for by the speed of the general laryngeal response.     

A perceptual comparison between paired stimulus and single stimulus methods of presentation of the fluent utterances of stutterers

This investigation compared tape recordings containing the fluent utterances of treated stutterers with those of normal speakers as paired stimuli and single stimuli as presented to 20 sophisticated judges. Fluent utterances were obtained from stutterers successfully treated in one of the following programs: (1) Van Riperian, (2) metronome-conditioning speech retraining, (3) delayed auditory feedback, (4) operant conditioning, (5) precision fluency shaping program, and (6) holistic therapy. In addition, a group of partially treated stutterers were included. The original tape recordings containing matched samples of the fluent utterances of a stutterer and normal speaker were presented as paired stimuli. These paired samples were then separated, randomized, and assembled individually on another tape recording and presented as single stimuli to the same judges. The results of the statistical analysis indicated that the fluent utterances of treated stutterers was perceptibly different from the fluent utterances of nonstutterers, regardless of the method of stimulus presentation.     

The use of the psychological stress evaluator with stutterers

A lie detection instrument, the Psychological Stress Evaluator, has been reported by the manufacturer as being capable of quantifying changes in the degree of “stress” as reflected by a subject's voice. Speech pathologists might consider the use of the instrument in clinical and research activities concerning the stutterer's emotional (stress) reaction to stuttering.To test the validity of the instrument, four stutterers and four normal speakers were recorded while making consecutive telephone calls. Randomized recordings were analyzed by a company trained technical to determine the degree of stress for each speech sample.Results indicated that both groups had a significant reduction of stress from the first to the fourth telephone call. However, the groups did not differ in the degree of stress during the ordered series of calls. Due to the inability of the Psychological Stress Evaluator to differentiate between the groups, the validity of the instruments is questioned.