Evaluation of a stuttering treatment based on reduction of short phonation intervals

Stuttering interventions for children, adolescents, and adults: a systematic review as a part of clinical guidelines

INTRODUCTION

Stuttering may have a holistic effect on the quality of life of a person who stutters by limiting participation in social situations, resulting in feelings of isolation and frustration, leading to difficulties in education and employment and increasing the likelihood of mental health problems. Even young children who stutter may have negative experiences of speaking. Therefore, it is important to treat stuttering behavior effectively in both children and adults. The purpose of this paper was to systematically review group and case studies about the effectiveness of behavioral stuttering interventions to provide evidence-based guidelines for clinicians.

METHODS

Systematic data retrieval was conducted in four electronic databases (PsycINFO, CINAHL, PubMed, Cochrane). The assessment of search results was conducted according to predetermined inclusion and exclusion criteria by two independent judges. The methodological quality of each paper was assessed using strict criteria to include only high-quality research.

RESULTS

The search revealed 2293 results, and 38 papers (systematic reviews N=3, group design studies N=21 and case studies N=14) with acceptable methodological quality were included. The data show that there is most evidence about the treatment of early childhood stuttering, very little evidence about school-aged children and some evidence about adults. The most convincing evidence is about the Lidcombe Program in the treatment of young children who stutter, but also other methods have promising evidence. Our data imply that in the treatment of adults who stutter, holistic treatments may influence speech fluency and overall experience of stuttering behavior. Speech restructuring treatments may have a positive effect on overt characteristics of stuttering, but not on covert stuttering behavior.

CONCLUSIONS

The results of this review agree with earlier reviews about the treatment of young children. However, due to different inclusion criteria, this review also shows the benefits of holistic treatment approaches with adults and adolescents.

Comparison of Stuttering Severity and Anxiety During Standard and Challenge Phone Calls

PURPOSE

This study was designed to answer three questions. (a) Does percentage of syllables stuttered (%SS) differ between standard and challenge phone calls. (b) Does anxiety differ between standard and challenge phone calls. (c) Is there a relationship between %SS and anxiety during standard and challenge phone calls?

METHOD

Participants were 230 adults diagnosed with stuttering, who were participants from five clinical trials. Each participant received two 10-min phone calls at pretreatment and a further two phone calls 6 months or 20 weeks postrandomization. One phone call was standard, and the other presented challenge: occasionally disagreeing with, interrupting, and talking over participants, or asking for clarification of their views.

RESULTS

Statistically significant, but clinically minor, increases of %SS and anxiety occurred during the challenge phone calls. There was a statistically significant association between %SS and anxiety.

CONCLUSIONS

Variable phone call procedures to assess stuttering severity in clinical trials are not likely to spuriously inflate or deflate treatment outcomes to a clinically important extent. Regardless, the present results suggest that there is statistical merit in controlling the nature of phone calls during clinical trials with the simple and replicable method developed in this report. Additionally, there is procedural merit in the challenge phone call procedure; it is a more valid representation of the challenges of everyday speech than the standard procedure. However, a disadvantage of the challenge phone call procedure is the practical issues associated with its use. The clinical and theoretical applications of the results are discussed.

The Speech Efficiency Score (SES): A time-domain measure of speech fluency

PURPOSE

This study is a preliminary attempt to evaluate a new speech fluency measure, the Speech Efficiency Score (SES), in comparison with subjective stuttering severity rating scales and stuttered syllable counts (%SS).

METHODS

277 listeners (92 naïve, 39 speech-language pathology (SLP) students, 124 practicing SLPs, and 22 SLPs who specialize in stuttering) evaluated short recordings of speech on an 11-point scale. Recordings were obtained from 56 adults, of whom 20 were people who stutter, 16 were people who stutter who were using fluency-shaping techniques, and 20 were speakers who do not stutter. In addition, %SS and the SES measure were obtained for each recording.

RESULTS

The four listener groups rated stuttering severity similarly, with no statistically significant between-group differences. Listeners' responses on the stuttering severity rating scales and the SES yielded significant differences between all three speaker groups. The %SS measure yielded a significant difference only between the stuttering group and the other two groups but not between the fluency-shaping and the control groups. A very strong positive correlation was found between the SES and the subjective stuttering-severity rating scales (r = 0.92). The correlation between %SS and the perceptual evaluation, as well as the correlation between %SS and the SES, were lower, though they still reached significance.

CONCLUSIONS

Results suggest that speech efficiency scores, which are based on a time-domain analysis, closely match subjective stuttering severity ratings and could ultimately provide a more objective way to measure speech fluency.

Stuttering treatment and brain research in adults: A still unfolding relationship

PURPOSE

Brain imaging and brain stimulation procedures have now been used for more than two decades to investigate the neural systems that contribute to the occurrence of stuttering in adults, and to identify processes that might enhance recovery from stuttering. The purpose of this paper is to review the extent to which these dual lines of research with adults who stutter have intersected and whether they are contributing towards the alleviation of this impairment.

METHOD

Several areas of research are reviewed in order to determine whether research on the neurology of stuttering is showing any potential for advancing the treatment of this communication disorder: (a) attempts to discover the neurology of stuttering, (b) neural changes associated with treated recovery, and (c) direct neural intervention.

RESULTS AND CONCLUSIONS

Although much has been learned about the neural underpinnings of stuttering, little research in any of the reviewed areas has thus far contributed to the advancement of stuttering treatment. Much of the research on the neurology of stuttering that does have therapy potential has been largely driven by a speech-motor model that is designed to account for the efficacy of fluency-inducing strategies and strategies that have been shown to yield therapy benefits. Investigations on methods that will induce neuroplasticity are overdue. Strategies profitable with other disorders have only occasionally been employed. However, there are signs that investigations on the neurology of adults who have recovered from stuttering are slowly being recognized for their potential in this regard.

Evidence, Goals, and Outcomes in Stuttering Treatment: Applications With an Adolescent Who Stutters

Purpose

The purpose of this clinical focus article is to summarize 1 possible process that a clinician might follow in designing and conducting a treatment program with John, a 14-year-old male individual who stutters.

Method

The available research evidence, practitioner experience, and consideration of individual preferences are combined to address goals, treatment procedures, and outcomes for John.

Conclusions

The stuttering treatment research literature includes multiple well-designed reviews and individual studies that have shown the effectiveness of prolonged speech (and smooth speech and related variations) for improving stuttered speech and for improving social, emotional, cognitive, and related variables in adolescents who stutter. Based on that evidence, and incorporating the additional elements of practitioner experience and client preferences, this clinical focus article suggests that John would be likely to benefit from a treatment program based on prolonged speech. The basic structure of 1 possible such program is also described, with an emphasis on the goals and outcomes that John could be expected to achieve.

Intrajudge and Interjudge Reliability of the Stuttering Severity Instrument-Fourth Edition

PURPOSE

The Stuttering Severity Instrument (SSI) is a tool used to measure the severity of stuttering. Previous versions of the instrument have known limitations (e.g., Lewis, 1995). The present study examined the intra- and interjudge reliability of the newest version, the Stuttering Severity Instrument-Fourth Edition (SSI-4) (Riley, 2009).

METHOD

Twelve judges who were trained on the SSI-4 protocol participated. Judges collected SSI-4 data while viewing 4 videos of adults who stutter at Time 1 and 4 weeks later at Time 2. Data were analyzed for intra- and interjudge reliability of the SSI-4 subscores (for Frequency, Duration, and Physical Concomitants), total score, and final severity rating.

RESULTS

Intra- and interjudge reliability across the subscores and total score concurred with the manual's reported reliability when reliability was calculated using the methods described in the manual. New calculations of judge agreement produced different values from those in the manual-for the 3 subscores, total score, and final severity rating-and provided data absent from the manual.

CONCLUSIONS

Clinicians and researchers who use the SSI-4 should carefully consider the limitations of the instrument. Investigation into the multitasking demands of the instrument may provide information on whether separating the collection of data for specific variables will improve intra- and interjudge reliability of those variables.

A real-time phoneme counting algorithm and application for speech rate monitoring

Adults who stutter can learn to control and improve their speech fluency by modifying their speaking rate. Existing speech therapy technologies can assist this practice by monitoring speaking rate and providing feedback to the patient, but cannot provide an accurate, quantitative measurement of speaking rate. Moreover, most technologies are too complex and costly to be used for home practice. We developed an algorithm and a smartphone application that monitor a patient's speaking rate in real time and provide user-friendly feedback to both patient and therapist. Our speaking rate computation is performed by a phoneme counting algorithm which implements spectral transition measure extraction to estimate phoneme boundaries. The algorithm is implemented in real time in a mobile application that presents its results in a user-friendly interface. The application incorporates two modes: one provides the patient with visual feedback of his/her speech rate for self-practice and another provides the speech therapist with recordings, speech rate analysis and tools to manage the patient's practice. The algorithm's phoneme counting accuracy was validated on ten healthy subjects who read a paragraph at slow, normal and fast paces, and was compared to manual counting of speech experts. Test-retest and intra-counter reliability were assessed. Preliminary results indicate differences of -4% to 11% between automatic and human phoneme counting. Differences were largest for slow speech. The application can thus provide reliable, user-friendly, real-time feedback for speaking rate control practice.

An investigation of the effects of a speech-restructuring treatment for stuttering on the distribution of intervals of phonation

PURPOSE

The purpose of this study was to investigate whether stuttering reductions following the instatement phase of a speech-restructuring treatment for adults were accompanied by reductions in the frequency of short intervals of phonation (PIs). The study was prompted by the possibility that reductions in the frequency of short PIs is the mechanism underlying such reductions in stuttering.

METHOD

The distribution of PIs was determined for seven adults who stutter, before and immediately after the intensive phase of a speech-restructuring treatment program. Audiovisual recordings of conversational speech were made on both assessment occasions, with PIs recorded with an accelerometer.

RESULTS

All seven participants had much lower levels of stuttering after treatment but these were associated with reductions in the frequency of short PIs for only four of them. For the other three participants, two showed no change in frequency of short PIs, while for the other participant the frequency of short PIs actually increased.

CONCLUSIONS

Stuttering reduction with speech-restructuring treatment can co-occur with reduction in the frequency of short PIs. However, the latter does not appear necessary for this reduction in stuttering to occur. Thus, speech-restructuring treatment must have other, or additional, treatment agents for stuttering to reduce.

Non-pharmacological treatments for stuttering in children and adults: a systematic review and evaluation of clinical effectiveness, and exploration of barriers to successful outcomes

BACKGROUND

Despite many years of research, there is no certainty regarding the cause of stuttering. Although numerous interventions have been developed, a broad-based systematic review across all forms of intervention for adults and children was needed including views and perceptions of people who stutter.

OBJECTIVE

The aims of the study were to report the clinical effectiveness of interventions for people who stutter (or clutter), to examine evidence regarding the views of people who stutter and the views of professionals regarding interventions.

DATA SOURCES

A systematic review of quantitative and qualitative literature was carried out between August 2013 and April 2014. The following electronic databases were searched: (1) MEDLINE, (2) EMBASE, (3) The Cochrane Library (including The Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, Database of Abstracts of Reviews of Effects, Health Technology Assessment Database and NHS Economic Evaluations Database), (4) PsycINFO, (5) Science Citation Index, (6) Social Science Citation Index, (7) Cumulative Index to Nursing and Allied Health Literature, (8) ASSIA, (9) Linguistics and Language Behavior Abstracts, (10) Sociological Abstracts and (11) the EPPI Centre. Reference lists of included papers and other reviews were screened and also key journals in the subject area were hand-searched.

REVIEW METHODS

The searches aimed to identify (1) evidence of clinical effectiveness in populations of pre-school children, school-aged children, adolescents and adults, and (2) data relating to perceptions of barriers and facilitators to intervention clinical effectiveness among staff and people who stutter. A metasynthesis of the two linked elements via development of a conceptual model was also carried out to provide further interpretation of the review findings.

RESULTS

A systematic search of the literature identified a large number of potentially relevant studies. Of these, 111 studies examining the clinical effectiveness of interventions, 25 qualitative papers and one mixed-methods paper met the criteria for inclusion in this review. Review of the effectiveness literature indicated evidence of positive outcomes across all types of interventions. Virtually all evidence we identified reported at least some positive effect for some participants. However, there was evidence of considerable individual variation in outcome for study participants. The qualitative literature highlighted the need for programmes to be tailored to individual need with variation at the levels of the intervention, the individual and interpersonal/social elements. Metasynthesis of the data highlighted the complexity of elements that need to be considered in evaluation of long-term impacts following stuttering interventions.

LIMITATIONS

Around two-thirds of the studies were considered to be at higher risk of bias. The heterogeneous nature and variability in outcomes meant that we were unable to complete a meta-analysis.

CONCLUSIONS

Although much of the evidence we identified was from studies at risk of bias, it is suggested that most available interventions for stuttering may be of benefit to at least some people who stutter. There is a requirement for greater clarity regarding what the core outcomes following stuttering intervention should be and also enhanced understanding of the process whereby interventions effect change. Further analysis of those for whom interventions have not produced a significant benefit may provide additional insights into the complex intervention-outcomes pathway.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42013004861.

Temporal variability in sung productions of adolescents who stutter

Singing has long been used as a technique to enhance and reeducate temporal aspects of articulation in speech disorders. In the present study, differences in temporal structure of sung versus spoken speech were investigated in stuttering. In particular, the question was examined if singing helps to reduce VOT variability of voiceless plosives, which would indicate enhanced temporal coordination of oral and laryngeal processes. Eight German adolescents who stutter and eight typically fluent peers repeatedly spoke and sang a simple German congratulation formula in which a disyllabic target word (e.g., /'ki:ta/) was repeated five times. Every trial, the first syllable of the word was varied starting equally often with one of the three voiceless German stops /p/, /t/, /k/. Acoustic analyses showed that mean VOT and stop gap duration reduced during singing compared to speaking while mean vowel and utterance duration was prolonged in singing in both groups. Importantly, adolescents who stutter significantly reduced VOT variability (measured as the Coefficient of Variation) during sung productions compared to speaking in word-initial stressed positions while the control group showed a slight increase in VOT variability. However, in unstressed syllables, VOT variability increased in both adolescents who do and do not stutter from speech to song. In addition, vowel and utterance durational variability decreased in both groups, yet, adolescents who stutter were still more variable in utterance duration independent of the form of vocalization. These findings shed new light on how singing alters temporal structure and in particular, the coordination of laryngeal-oral timing in stuttering. Future perspectives for investigating how rhythmic aspects could aid the management of fluent speech in stuttering are discussed.

LEARNING OUTCOMES

Readers will be able to describe (1) current perspectives on singing and its effects on articulation and fluency in stuttering and (2) acoustic parameters such as VOT variability which indicate the efficiency of control and coordination of laryngeal-oral movements. They will understand and be able to discuss (3) how singing reduces temporal variability in the productions of adolescents who do and do not stutter and 4) how this is linked to altered articulatory patterns in singing as well as to its rhythmic structure.

The state of the art in non-pharmacological interventions for developmental stuttering. Part 1: a systematic review of effectiveness

BACKGROUND

The growing range of available treatment options for people who stutter presents a challenge for clinicians, service managers and commissioners, who need to have access to the best available treatment evidence to guide them in providing the most appropriate interventions. While a number of reviews of interventions for specific populations or a specific type of intervention have been carried out, a broad-based systematic review across all forms of intervention for adults and children was needed to provide evidence to underpin future guidelines, inform the implementation of effective treatments and identify future research priorities.

AIMS

To identify and synthesize the published research evidence on the clinical effectiveness of the broad range of non-pharmacological interventions for the management of developmental stuttering.

METHODS & PROCEDURES

A systematic review of the literature reporting interventions for developmental stuttering was carried out between August 2013 and April 2014. Searches were not limited by language or location, but were restricted by date to studies published from 1990 onwards. Methods for the identification of relevant studies included electronic database searching, reference list checking, citation searching and hand searching of key journals. Appraisal of study quality was performed using a tool based on established criteria for considering risk of bias. Due to heterogeneity in intervention content and outcomes, a narrative synthesis was completed.

MAIN CONTRIBUTION

The review included all available types of intervention and found that most may be of benefit to at least some people who stutter. There was evidence, however, of considerable individual variation in response to these interventions. The review indicated that effects could be maintained following all types of interventions (although this was weakest with regard to feedback and technology interventions).

CONCLUSIONS

This review highlights a need for greater consensus with regard to the key outcomes used to evaluate stuttering interventions, and also a need for enhanced understanding of the process whereby interventions effect change. Further analysis of the variation in effectiveness for different individuals or groups is needed in order to identify who may benefit most from which intervention.

Efficacy of the Modifying Phonation Intervals (MPI) Stuttering Treatment Program With Adults Who Stutter

PURPOSE

This study compared a new adult stuttering treatment program (Modifying Phonation Intervals, or MPI) with the standard of care for reducing stuttered speech in adults (prolonged speech).

METHOD

Twenty-seven adults who stutter were assigned to either MPI or prolonged speech treatment, both of which used similar infrastructures. Speech and related variables were assessed in 3 within-clinic and 3 beyond-clinic speaking situations for participants who successfully completed all treatment phases.

RESULTS

At transfer, maintenance, and follow-up, the speech of 14 participants who successfully completed treatment was similar to that of normally fluent adults. Successful participants also showed increased self-identification as a "normal speaker," decreased self-identification as a "stutterer," reduced short intervals of phonation, and some increased use of longer duration phonation intervals. Eleven successful participants received the MPI treatment, and 3 received the prolonged speech treatment.

CONCLUSIONS

Outcomes for successful participants were very similar for the 2 treatments. The much larger proportion of successful participants in the MPI group, however, combined with the predictive value of specific changes in PI durations suggest that MPI treatment was relatively more effective at assisting clients to identify and change the specific speech behaviors that are associated with successful treatment of stuttered speech in adults.

Absolute and relative reliability of percentage of syllables stuttered and severity rating scales

PURPOSE

Percentage of syllables stuttered (%SS) and severity rating (SR) scales are measures in common use to quantify stuttering severity and its changes during basic and clinical research conditions. However, their reliability has not been assessed with indices measuring both relative and absolute reliability. This study was designed to provide such information. Relative reliability deals with the rank order of participants in a sample, whereas absolute reliability measures the closeness of scores to one other and to a hypothetical true score.

METHOD

Eighty-seven adult participants who stutter received a 10-min unscheduled telephone call. Three experienced judges measured %SS and also used a 9-point SR scale to measure stuttering severity from recordings of the telephone calls.

RESULTS

Relative intrajudge and interjudge reliability were satisfactory for both scales. However, absolute intrajudge and interjudge reliability were not satisfactory. Results showed that paired-judge SR and %SS procedures improved absolute reliability compared with single-judge measures. Additionally, the paired-judge procedure improved relative reliability from high to very high levels.

CONCLUSION

Measurement of group changes of stuttering severity can be done in research contexts using either %SS or SR. However, for detecting changes within individuals using such measures, a paired-judge procedure is a more reliable method.

Systematic studies of modified vocalization: the effect of speech rate on speech production measures during metronome-paced speech in persons who stutter

BACKGROUND

Metronome-paced speech results in the elimination, or substantial reduction, of stuttering moments. The cause of fluency during this fluency-inducing condition is unknown. Several investigations have reported changes in speech pattern characteristics from a control condition to a metronome-paced speech condition, but failure to control speech rate between conditions limits our ability to determine if the changes were necessary for fluency.

AIMS

This study examined the effect of speech rate on several speech production variables during one-syllable-per-beat metronomic speech in order to determine changes that may be important for fluency during this fluency-inducing condition.

METHODS & PROCEDURES

Thirteen persons who stutter (PWS), aged 18-62 years, completed a series of speaking tasks. Several speech production variables were compared between conditions produced at different metronome beat rates, and between a control condition and a metronome-paced speech condition produced at a rate equal to the control condition.

OUTCOMES & RESULTS

Vowel duration, voice onset time, pressure rise time and phonated intervals were significantly impacted by metronome beat rate. Voice onset time and the percentage of short (30-100 ms) phonated intervals significantly decreased from the control condition to the equivalent rate metronome-paced speech condition.

CONCLUSIONS & IMPLICATIONS

A reduction in the percentage of short phonated intervals may be important for fluency during syllable-based metronome-paced speech for PWS. Future studies should continue examining the necessity of this reduction. In addition, speech rate must be controlled in future fluency-inducing condition studies, including neuroimaging investigations, in order for this research to make a substantial contribution to finding the fluency-inducing mechanism of fluency-inducing conditions.

Regional brain activity change predicts responsiveness to treatment for stuttering in adults

Developmental stuttering is known to be associated with aberrant brain activity, but there is no evidence that this knowledge has benefited stuttering treatment. This study investigated whether brain activity could predict progress during stuttering treatment for 21 dextral adults who stutter (AWS). They received one of two treatment programs that included periodic H2(15)O PET scanning (during oral reading, monologue, and eyes-closed rest conditions). All participants successfully completed an initial treatment phase and then entered a phase designed to transfer treatment gains; 9/21 failed to complete this latter phase. The 12 pass and 9 fail participants were similar on speech and neural system variables before treatment, and similar in speech performance after the initial phase of their treatment. At the end of the initial treatment phase, however, decreased activation within a single region, L. putamen, in all 3 scanning conditions was highly predictive of successful treatment progress.

Using statistical process control charts to study stuttering frequency variability during a single day

PURPOSE

Stuttering varies between and within speaking situations. In this study, the authors used statistical process control charts with 10 case studies to investigate variability of stuttering frequency.

METHOD

Participants were 10 adults who stutter. The authors counted the percentage of syllables stuttered (%SS) for segments of their speech during different speaking activities over a 12-hr day. Results for each participant were plotted on control charts.

RESULTS

All participants showed marked variation around mean stuttering frequency. However, there was no pattern of that variation consistent across the 10 participants. According to control charts, the %SS scores of half the participants were indicative of unpredictable, out-of-control systems, and the %SS scores of the other half of the participants were not. Self-rated stuttering severity and communication satisfaction correlated significantly and intuitively with the number of times participants exceeded their upper control chart limits.

CONCLUSIONS

Control charts are a useful method to study how %SS scores might be applied to the study of stuttering variability during research and clinical practice. However, the method presents some practical problems, and the authors discuss how those problems can be solved. Solving those problems would enable researchers and clinicians to better plan, conduct, and evaluate stuttering treatments.

The effect of speech rate on stuttering frequency, phonated intervals, speech effort, and speech naturalness during chorus reading

PURPOSE

This study examined the effect of speech rate on phonated intervals (PIs), in order to test whether a reduction in the frequency of short PIs is an important part of the fluency-inducing mechanism of chorus reading. The influence of speech rate on stuttering frequency, speaker-judged speech effort, and listener-judged naturalness was also examined. An added purpose was to determine if chorus reading could be further refined so as to provide a perceptual guide for gauging the level of physical effort exerted during speech production.

METHODS

A repeated-measures design was used to compare data obtained during control reading conditions and during several chorus reading conditions produced at different speech rates. Participants included 8 persons who stutter (PWS) between the ages of 16 and 32 years.

RESULTS

There were significant reductions in the frequency of short PIs from the habitual reading condition during slower chorus conditions, no change when speech rates were matched between habitual reading and chorus conditions, and an increase in the frequency of short PIs during chorus reading produced at a faster rate than the habitual condition. Speech rate did not have an effect on stuttering frequency during chorus reading. In general, speech effort ratings improved and naturalness ratings worsened as speech rate decreased.

CONCLUSION

These results provide evidence that (a) a reduction in the frequency of short PIs is not necessary for fluency improvement during chorus reading, and (b) speech rate may be altered to provide PWS with a more appropriate reference for how physically effortful normally fluent speech production should be. Future investigations should examine the necessity of changes in the activation of neural regions during chorus reading, the possibility of defining individualized units on a 9-point effort scale, and if there are upper and lower speech rate boundaries for receiving ratings of "highly natural sounding" speech during chorus reading.

LEARNING OUTCOMES

The reader will be able to: (1) describe the effect of changes in speech rate on the frequency of short phonated intervals during chorus reading, (2) describe changes to speaker-judged speech effort as speech rate changes during chorus reading, (3) and describe the effect of changes in speech rate on listener-judged naturalness ratings during chorus reading.

Theory and therapy in stuttering: a complex relationship

There are many treatments currently available for stuttering, for both children and adults. These range from direct interventions intended to reduce the severity and/or frequency of the speech behaviors of stuttering, to those intended to alleviate the anxiety and other mental health issues that can accompany the disorder. However, as there are little supporting data for many of these treatments, there is little consensus about which to use. Another way to evaluate stuttering treatments is to explore the extent to which they address the cause of the disorder. However, the cause of stuttering is not yet known. In this theoretical paper, a 3-factor causal model is presented, to which the mechanisms thought to be driving different treatments are then aligned. The model is innovative, in that it attempts to explain moments of stuttering. It is argued that all causal factors must be operating at each moment of stuttering. The model is intended as a new way of looking at cause, and how treatments may address cause. It is hoped this will stimulate discussion and lead to further lines of inquiry.

EDUCATIONAL OBJECTIVES

The reader will be able to: (a) describe the P&A 3-factor causal model of moments of stuttering; (b) state how indirect direct stuttering treatments relate to cause, according to the P&A model; (c) describe how direct stuttering treatments relate to cause, according to the P&A model; (d) state the purpose of cognitive behavior therapy; and (e) describe at least one suggestion for further research arising from the P&A model.

Integrating functional measures with treatment: a tactic for enhancing personally significant change in the treatment of adults and adolescents who stutter

PURPOSE

It is proposed that stuttering treatment, particularly for adults and adolescents who stutter, may benefit from more inventive and extensive use of functional measurement-measures that are also treatment agents. Such measures can be tailored to produce more personally significant and evidence-based treatment benefits. They may be especially useful when employed in conjunction with partial self-management and performance-contingent procedures.

METHOD

Previous approaches to the definition of stuttering treatment goals and the measurement of stuttering treatment outcomes are critically reviewed. Suggestions for improvements are presented within the framework of an evidence-based and relatively standardized stuttering treatment.

RESULTS AND CONCLUSION

Results from a review of existing literature and from 2 case studies show that 2 specific personally significant problems, saying one's name and addressing large audiences, were improved by implementing these strategies in treatment. Functional measures directly connected to treatment, and partially self-managed performance-contingent schedules, merit further research as methodologies that are suitable for conducting personally significant and evidence-based treatments with adults and adolescents who stutter.

Phonation interval modification and speech performance quality during fluency-inducing conditions by adults who stutter

PURPOSE

To relate changes in four variables previously defined as characteristic of normally fluent speech to changes in phonatory behavior during oral reading by persons who stutter (PWS) and normally fluent controls under multiple fluency-inducing (FI) conditions.

METHOD

Twelve PWS and 12 controls each completed 4 ABA experiments. During A phases, participants read normally. B phases were 4 different FI conditions: auditory masking, chorus reading, whispering, and rhythmic stimulation. Dependent variables were the durations of accelerometer-recorded phonated intervals; self-judged speech effort; and observer-judged stuttering frequency, speech rate, and speech naturalness. The method enabled a systematic replication of Ingham et al. (2009).

RESULTS

All FI conditions resulted in decreased stuttering and decreases in the number of short phonated intervals, as compared with baseline conditions, but the only FI condition that satisfied all four characteristics of normally fluent speech was chorus reading. Increases in longer phonated intervals were associated with decreased stuttering but also with poorer naturalness and/or increased speech effort. Previous findings concerning the effects of FI conditions on speech naturalness and effort were replicated.

CONCLUSIONS

Measuring all relevant characteristics of normally fluent speech, in the context of treatments that aim to reduce the occurrence of short-duration PIs, may aid the search for an explanation of the nature of stuttering and may also maximize treatment outcomes for adults who stutter.

LEARNING OUTCOMES

The reader will be able to (1) understand the differential effects of four well established fluency-inducing conditions on the quality of fluency of adult PWS and controls, (2) learn how intervals of phonation are modified during these conditions and (3) how the duration of specific intervals of phonation may be identified for their potential application in stuttering treatment.

Comments on recent developments in stuttering treatment maintenance research using the Camperdown Program

PURPOSE

To review the contribution of recent studies on the Camperdown Program (O'Brian, Onslow, Cream, & Packman, 2003) for treating stuttering in adolescents and adults toward the problem of maintenance of treatment benefits.

METHOD

The procedures employed in those studies are reviewed with respect to the use of performance-contingent maintenance schedules, including their recent use in conjunction with social anxiety modification.

CONCLUSION

The design of the recent studies of the Camperdown Program confounds the effects of maintenance strategies and treatment outcome evaluation, thereby obscuring their contribution toward resolving the problem of maintenance.

Reprint of: technology and the evolution of clinical methods for stuttering

The World Wide Web (WWW) was 20 years old last year. Enormous amounts of information about stuttering are now available to anyone who can access the Internet. Compared to 20 years ago, people who stutter and their families can now make more informed choices about speech-language interventions, from a distance. Blogs and chat rooms provide opportunities for people who stutter to share their experiences from a distance and to support one another. New technologies are also being adopted into speech-language pathology practice and service delivery. Telehealth is an exciting development as it means that treatment can now be made available to many rural and remotely located people who previously did not have access to it. Possible future technological developments for speech-language pathology practice include Internet based treatments and the use of Virtual Reality. Having speech and CBT treatments for stuttering available on the Internet would greatly increase their accessibility. Second Life also has exciting possibilities for people who stutter.

EDUCATIONAL OBJECTIVES

The reader will (1) explain how people who stutter and their families can get information about stuttering from the World Wide Web, (2) discuss how new technologies have been applied in speech-language pathology practice, and (3) summarize the principles and practice of telehealth delivery of services for people who stutter and their families.

Systematic studies of modified vocalization: speech production changes during a variation of metronomic speech in persons who do and do not stutter

The most common way to induce fluency using rhythm requires persons who stutter to speak one syllable or one word to each beat of a metronome, but stuttering can also be eliminated when the stimulus is of a particular duration (e.g., 1 second [s]). The present study examined stuttering frequency, speech production changes, and speech naturalness during rhythmic speech that alternated 1s of reading with 1s of silence. A repeated-measures design was used to compare data obtained during a control reading condition and during rhythmic reading in 10 persons who stutter (PWS) and 10 normally fluent controls. Ratings for speech naturalness were also gathered from naïve listeners. Results showed that mean vowel duration increased significantly, and the percentage of short phonated intervals decreased significantly, for both groups from the control to the experimental condition. Mean phonated interval length increased significantly for the fluent controls. Mean speech naturalness ratings during the experimental condition were approximately "7" on a 1-9 scale (1=highly natural; 9=highly unnatural), and these ratings were significantly correlated with vowel duration and phonated intervals for PWS. The findings indicate that PWS may be altering vocal fold vibration duration to obtain fluency during this rhythmic speech style, and that vocal fold vibration duration may have an impact on speech naturalness during rhythmic speech. Future investigations should examine speech production changes and speech naturalness during variations of this rhythmic condition.

EDUCATIONAL OBJECTIVES

The reader will be able to: (1) describe changes (from a control reading condition) in speech production variables when alternating between 1s of reading and 1s of silence, (2) describe which rhythmic conditions have been found to sound and feel the most natural, (3) describe methodological issues for studies about alterations in speech production variables during fluency-inducing conditions, and (4) describe which fluency-inducing conditions have been shown to involve a reduction in short phonated intervals.

Technology and the evolution of clinical methods for stuttering

The World Wide Web (WWW) was 20 years old last year. Enormous amounts of information about stuttering are now available to anyone who can access the Internet. Compared to 20 years ago, people who stutter and their families can now make more informed choices about speech-language interventions, from a distance. Blogs and chat rooms provide opportunities for people who stutter to share their experiences from a distance and to support one another. New technologies are also being adopted into speech-language pathology practice and service delivery. Telehealth is an exciting development as it means that treatment can now be made available to many rural and remotely located people who previously did not have access to it. Possible future technological developments for speech-language pathology practice include Internet based treatments and the use of Virtual Reality. Having speech and CBT treatments for stuttering available on the Internet would greatly increase their accessibility. Second Life also has exciting possibilities for people who stutter.

EDUCATIONAL OBJECTIVES

The reader will (1) explain how people who stutter and their families can get information about stuttering from the World Wide Web, (2) discuss how new technologies have been applied in speech-language pathology practice, and (3) summarize the principles and practice of telehealth delivery of services for people who stutter and their families.

Systematic studies of modified vocalization: effects of speech rate and instatement style during metronome stimulation

PURPOSE

This study introduces a series of systematic investigations intended to clarify the parameters of the fluency-inducing conditions (FICs) in stuttering.

METHOD

Participants included 11 adults, aged 20-63 years, with typical speech-production skills. A repeated measures design was used to examine the relationships between several speech production variables (vowel duration, voice onset time, fundamental frequency, intraoral pressure, pressure rise time, transglottal airflow, and phonated intervals) and speech rate and instatement style during metronome-entrained rhythmic speech.

RESULTS

Measures of duration (vowel duration, voice onset time, and pressure rise time) differed across different metronome conditions. When speech rates were matched between the control condition and metronome condition, voice onset time was the only variable that changed.

CONCLUSION

Results confirm that speech rate and instatement style can influence speech production variables during the production of fluency-inducing conditions. Future studies of normally fluent speech and of stuttered speech must control both features and should further explore the importance of voice onset time, which may be influenced by rate during metronome stimulation in a way that the other variables are not.

Overreliance on auditory feedback may lead to sound/syllable repetitions: simulations of stuttering and fluency-inducing conditions with a neural model of speech production

This paper investigates the hypothesis that stuttering may result in part from impaired readout of feedforward control of speech, which forces persons who stutter (PWS) to produce speech with a motor strategy that is weighted too much toward auditory feedback control. Over-reliance on feedback control leads to production errors which if they grow large enough, can cause the motor system to "reset" and repeat the current syllable. This hypothesis is investigated using computer simulations of a "neurally impaired" version of the DIVA model, a neural network model of speech acquisition and production. The model's outputs are compared to published acoustic data from PWS' fluent speech, and to combined acoustic and articulatory movement data collected from the dysfluent speech of one PWS. The simulations mimic the errors observed in the PWS subject's speech, as well as the repairs of these errors. Additional simulations were able to account for enhancements of fluency gained by slowed/prolonged speech and masking noise. Together these results support the hypothesis that many dysfluencies in stuttering are due to a bias away from feedforward control and toward feedback control.

EDUCATIONAL OBJECTIVES

The reader will be able to (a) describe the contribution of auditory feedback control and feedforward control to normal and stuttered speech production, (b) summarize the neural modeling approach to speech production and its application to stuttering, and (c) explain how the DIVA model accounts for enhancements of fluency gained by slowed/prolonged speech and masking noise.

Five-year longitudinal treatment outcomes of the ISTAR Comprehensive Stuttering Program

Replicated evidence of satisfactory 1- and 2-year post-treatment outcomes has been reported for the Comprehensive Stuttering Program (CSP). However, little is known about longer term outcomes of the CSP. Yearly follow-up measures were obtained from 18 participants for 5 consecutive years. At 5-year follow-up, participants were maintaining clinically and statistically significant reductions in stuttering and increases in rates of speech relative to pre-treatment measures. Standardized effect sizes were large. There were no significant differences among the immediate post-treatment and five follow-up measures, indicating that speech gains achieved by the end of the treatment program were stable over the 5-year follow-up period. Insufficient return rates for self-report data for the third to fifth follow-up measurement occasions prohibited analyzing these data. However, non-significant differences among the immediate post-treatment and two follow-up measures indicated that improvements achieved by the end of treatment in speech-related confidence, and perceptions of struggle, avoidance, and expectancy to stutter were stable over the 2-year follow-up period. Significant differences among the speech-related communication attitudes scores indicated that improvements in attitudes made at the end of the treatment program were less stable. Taken together, these results provide further and longer term evidence of the effectiveness of the CSP.

EDUCATIONAL OBJECTIVES

Readers will be able to: (1) describe the main components of the Comprehensive Stuttering Program (2) describe a methodology for determining clinically meaningful maintenance of stuttering reductions, and (3) describe the durability and stability of improvements in speech and self-report measures across time.

Measurement of speech effort during fluency-inducing conditions in adults who do and do not stutter

PURPOSE

To investigate the effects of 4 fluency-inducing (FI) conditions on self-rated speech effort and other variables in adults who stutter and in normally fluent controls.

METHOD

Twelve adults with persistent stuttering and 12 adults who had never stuttered each completed 4 ABA-format experiments. During A phases, participants read aloud normally. During each B phase, they read aloud in 1 of 4 FI conditions: auditory masking, chorus reading, whispering, and rhythmic speech. Dependent variables included self-judged speech effort and observer-judged stuttering frequency, speech rate, and speech naturalness.

RESULTS

For the persons who stuttered, FI conditions reduced stuttering and speech effort, but only for chorus reading were these improvements obtained without diminishing speech naturalness or speaking rate. By contrast, speech effort increased during all FI conditions for adults who did not stutter.

CONCLUSIONS

Self-rated speech effort differentiated the effects of 4 FI conditions on speech performance for adults who stuttered, with chorus reading best approximating normally fluent speech. More generally, self-ratings of speech effort appeared to constitute an independent, reliable, and validly interpretable dimension of fluency that may be useful in the measurement and treatment of stuttering.

Claims of a ‘new’ stuttering treatment using time-out from speaking are exaggerated: A brief review of the literature and commentary on Hewat et al. (2006)

In a recent article, Hewat et al. 1 claimed to have developed novel procedures for treating stuttering. The present article reviews relevant literature, and shows that the Hewat et al. claims of originality are exaggerated. It is concluded that the Hewat et al. study includes conceptual and methodological weaknesses that render their findings predominantly uninterpretable.

Evidence-based treatment and stuttering--historical perspective

PURPOSE

To illustrate the way in which both fluency shaping (FS) and stuttering management (SM) treatments for developmental stuttering in adults are evidence based.

METHOD

A brief review of the history and development of FS and SM is provided. It illustrates that both can be justified as evidence-based treatments, each treatment seeking evidence of a different kind: FS seeks evidence concerning treatment outcome, and SM seeks evidence concerning the nature of the stutter event.

CONCLUSION

Although outcome evidence provides the principal support for FS, support for SM comes principally from a cognitive learning model of defensive behavior as applied to the nature of the stutter event. Neither approach can claim anything like uniform success with adults who stutter. However, self-management and modeling are strategies common to both approaches and have shown consistently positive effects on outcome. It is argued that both strategies merit additional treatment efficacy study. Cognitive behavior theory may provide a useful framework for this research.

Measurement of phonated intervals during four fluency-inducing conditions

PURPOSE

Previous investigations of persons who stutter have demonstrated changes in vocalization variables during fluency-inducing conditions (FICs). A series of studies has also shown that a reduction in short intervals of phonation, those from 30 to 200 ms, is associated with decreased stuttering. The purpose of this study, therefore, was to test the hypothesis that the distribution of phonated intervals (PIs) should change during 4 of the most well-known FICs.

METHOD

A repeated-measures design was used to explore the relationship between PIs and stuttering during 4 FICs: chorus reading, prolonged speech, singing, and rhythmic stimulation. Most conditions were conducted at 2 different speech rates. The distribution of PIs was measured during these conditions and was compared with PI distributions obtained during control conditions.

RESULTS

Overall PI distributions were significantly different during all 4 FICs, as compared with control conditions. PIs in the range of 30-150 ms were reduced across all FICs, at all speech rates.

CONCLUSION

These results provide further evidence of the importance of phonation variables to (a) our understanding of how FICs may operate and (b) the treatment of stuttering. These findings, along with previous studies that showed how purposefully reducing the number of short PIs resulted in the elimination of stuttering, suggest that treatment programs based on prolonged speech-or PIs, in particular-may benefit from emphasizing a reduction in the number of short PIs and a simultaneous increase in the number of longer PIs.

Defining, identifying, and evaluating clinical trials of stuttering treatments: a tutorial for clinicians

PURPOSE

To develop a method for clinicians to evaluate stuttering treatment efficacy research with very little burden of work.

METHOD

The clinical trial is the most fundamental, clinically interpretable, and useful output unit of stuttering treatment research. We define a clinical trial of a stuttering treatment and specify 3 levels of clinical trials evidence. We use this taxonomy to identify and evaluate clinical trials of stuttering treatment. Our taxonomy draws on 2 fundamental principles of clinical trials used to evaluate health care: randomization and effect size.

RESULTS

Published clinical trials of stuttering treatments were identified and allocated to 1 of 3 levels of evidence.

CONCLUSIONS

We outline a 3-step, semi-automated, Internet-based method to identify the publication of a report of stuttering treatment efficacy. For a report identified as such, a 10-item checklist is applied to verify its status as a clinical trial and to allocate it to 1 of 3 levels of clinical trials evidence. The present taxonomy reduces the burden of work of a 136-item checklist in an existing taxonomy.

Developing Treatment for Adolescents Who Stutter: A Phase I Trial of the Camperdown Program

Purpose

To investigate in detail how adolescents who stutter perform during treatment, with the aim of informing treatment development for this age group.

Method

The Camperdown Program was conducted with 3 adolescents who stutter. Their performance during treatment was recorded in detail, and outcome measures were collected before treatment and on 5 occasions after treatment.

Results

One participant responded extremely well to treatment, with percentage of syllables stuttered (%SS) scores at 12 months follow-up around 1%. In addition, his speech naturalness was within normal limits. Another participant withdrew from treatment during maintenance, yet he still approximately halved his pretreatment %SS scores and was also sounding natural after treatment. This participant was satisfied with his treatment outcome. A third participant did not reach maintenance and did not benefit from the treatment.

Conclusion

The adolescent who succeeded in treatment presented with a high level of self-confidence and maturity. When examining the factors that seemed to impact on treatment outcome, an underlying theme of decreased parent influence and increased peer influence and self-direction was detected. These are fundamental during the journey through adolescence from childhood to adulthood. Future directions in developing treatments for adolescents are discussed.

Telehealth delivery of the Camperdown Program for adults who stutter: a phase I trial

PURPOSE

This Phase I trial investigated the viability of telehealth delivery of the Camperdown Program with adults who stutter. This program involves speech restructuring.

METHOD

All treatment was conducted remotely with participant-clinician contact occurring by telephone and e-mail.

RESULTS

Ten adults completed the program. The group showed an 82% reduction in stuttering frequency immediately after treatment and a 74% reduction 6 months after treatment. However, there was significant individual variation in response to the program.

CONCLUSION

These preliminary data suggest that telehealth Camperdown has the potential to provide efficacious treatment for clients who do not have access to traditional face-to-face treatment.

Stuttering treatment research 1970-2005: I. Systematic review incorporating trial quality assessment of behavioral, cognitive, and related approaches

PURPOSE

To complete a systematic review, with trial quality assessment, of published research about behavioral, cognitive, and related treatments for developmental stuttering. Goals included the identification of treatment recommendations and research needs based on the available high-quality evidence about stuttering treatment for preschoolers, school-age children, adolescents, and adults.

METHOD

Multiple readers reviewed 162 articles published between 1970 and 2005, using a written data extraction instrument developed as a synthesis of existing standards and recommendations. Articles were then assessed using 5 methodological criteria and 4 outcomes criteria, also developed from previously published recommendations.

RESULTS

Analyses found 39 articles that met at least 4 of the 5 methodological criteria and were considered to have met a trial quality inclusion criterion for the purposes of this review. Analysis of those articles identified a range of stuttering treatments that met speech-related and/or social, emotional, or cognitive outcomes criteria.

CONCLUSIONS

Review of studies that met the trial quality inclusion criterion established for this review suggested that response-contingent principles are the predominant feature of the most powerful treatment procedures for young children who stutter. The most powerful treatments for adults, with respect to both speech outcomes and social, emotional, or cognitive outcomes, appear to combine variants of prolonged speech, self-management, response contingencies, and other infrastructural variables. Other specific clinical recommendations for each age group are provided, as are suggestions for future research.

Connecting stuttering management and measurement: I. Core speech measures of clinical process and outcome

BACKGROUND

There will always be a place for stuttering treatments designed to eliminate or reduce stuttered speech. When those treatments are required, direct speech measures of treatment process and outcome are needed in clinical practice.

AIMS

Based on the contents of published clinical trials of such treatments, three 'core' measures of treatment outcome are presented for consideration by clinicians: measures of stuttering rate, speech rate and speech naturaleness.

MAIN CONTRIBUTION

In contrast to clinical trials, however, clinicians are at liberty to have as many outcome measures as thought necessary, and to design non-standard ones to suit their needs and those of their clients. In that context, the merits of severity ratings of stuttering are considered. It is argued that the prime source of guidance of suitable measures of treatment process are the manuals of the treatments that have figured in clinical trials.

CONCLUSIONS

Although there are independent data sources that contradict the axiom that treatment outcomes should be measured beyond the clinic, it is argued that it is premature to dispense with beyond-clinic process outcome measures for clinical practice. It is argued that for clinicians who conduct treatments in non-research contexts, one pretreatment outcome measurement occasion is sufficient, along with post-treatment measures at each maintenance visit. More than anything else, the numerous advantages of severity ratings of stuttering facilitate clinical measurement of treatment outcome and treatment process in several settings and on several occasions.

Speech effort measurement and stuttering: investigating the chorus reading effect

PURPOSE

The purpose of this study was to investigate chorus reading's (CR's) effect on speech effort during oral reading by adult stuttering speakers and control participants. The effect of a speech effort measurement highlighting strategy was also investigated.

METHOD

Twelve persistent stuttering (PS) adults and 12 normally fluent control participants completed 1-min base rate readings (BR-nonchorus) and CRs within a BR/CR/BR/CR/BR experimental design. Participants self-rated speech effort using a 9-point scale after each reading trial. Stuttering frequency, speech rate, and speech naturalness measures were also obtained. Instructions highlighting speech effort ratings during BR and CR phases were introduced after the first CR.

RESULTS

CR improved speech effort ratings for the PS group, but the control group showed a reverse trend. Both groups' effort ratings were not significantly different during CR phases but were significantly poorer than the control group's effort ratings during BR phases. The highlighting strategy did not significantly change effort ratings.

CONCLUSION

The findings show that CR will produce not only stutter-free and natural sounding speech but also reliable reductions in speech effort. However, these reductions do not reach effort levels equivalent to those achieved by normally fluent speakers, thereby conditioning its use as a gold standard of achievable normal fluency by PS speakers.

The Stuttering Treatment Research Evaluation and Assessment Tool (STREAT): evaluating treatment research as part of evidence-based practice

PURPOSE

This article presents, and explains the issues behind, the Stuttering Treatment Research Evaluation and Assessment Tool (STREAT), an instrument created to assist clinicians, researchers, students, and other readers in the process of critically appraising reports of stuttering treatment research.

METHOD

The STREAT was developed by combining and reorganizing previously published recommendations about the design and conduct of stuttering treatment research.

CONCLUSIONS

If evidence-based practice is to be widely adopted as the basis for stuttering assessment and treatment, procedures must be developed and distributed that will allow students, clinicians, and other readers without specialized knowledge of research design to critically appraise treatment research reports. The STREAT is intended to be such an instrument: It represents the consensus of previous methodological recommendations; it is consistent with and complements existing recommendations in evidence-based medicine and in the broader science of treatment outcome evaluation; and it is formatted into a single instrument for ease of use.

The distribution of phonated intervals in the speech of individuals who stutter

PURPOSE

Previous research has demonstrated the fluency-improving effect of reducing the occurrence of short-duration, phonated intervals (PIs; approximately 30-150 ms) in individuals who stutter, prompting the hypothesis that PIs in these individuals' speech are not distributed normally, particularly in the short PI ranges. It has also been hypothesized that this nonnormal PI distribution will be present during the stutter-free speech of affected persons.

METHOD

A comparison was made between the distributions of PIs during oral reading by adolescent and adult speakers who stuttered (n=13; 11 males) and by age- and gender-matched, normally fluent control participants.

RESULTS

The results did not support these hypotheses. The results showed that although there were significantly fewer PIs in the speech of the speakers who stuttered (probably because of their slower speaking rate), there was no significant difference between the PI distributions of both speaker groups. This was also true for comparisons between the stutter-free speech of the affected speakers and matched periods of speech produced by the control participants. The PI distributions from both groups were highly correlated.

CONCLUSION

The null hypothesis findings are discussed in relation to speech-motor- and neurologic-systems explanations for the fluency-inducing effects of reducing short PIs in the speech of individuals who stutter.

Recent advances in the treatment of stuttering: a theoretical perspective

Prolonged speech and its variants are widely used in the behavioral treatment of stuttering. Unlike these approaches, which depend on clinician-prescribed speech pattern changes, two behavioral treatment regimens, one for children and another for adults, recently developed at the Australian Stuttering Research Center, promote self-monitoring of speech as a means of controlling stuttering. In these programs, the clients themselves modify their speech in subtle and variable ways to gain control over stuttering and, in that, they appear to be similar to a well-known experimental technique for suppressing stutters known as response contingent stimulation. The present paper provides an integrated explanation for the effectiveness of both clinician-directed as well as client-initiated speech pattern modifications and, in the process, develops a new model of stuttering. It also shows why client-generated speech patterns changes potentially produce faster and more lasting improvement than those changes prescribed by a clinician.

LEARNING OUTCOMES

The reader will learn about: (1) two hypothesized methods of preparing utterance motor plans--speech concatenation and speech construction; (2) how behavioral treatment programs make use of speech construction to promote fluency in persons who stutter; (3) why therapy procedures based on cognitively driven speech construction produce faster and superior results than those based on motorically driven speech construction; and (4) the empirical evidence that suggests that speech concatenation is the source of stuttering.

A Critique of Venkatagiri's Hypothesis (2004) about the Cause of Stuttering

This paper critiques a recent proposed causal hypothesis of stuttering. It is argued that the proposal is a classic example of the misuse of the representativeness heuristic in the search for the cause of the disorder.

Intensive stuttering modification therapy: a multidimensional assessment of treatment outcomes

Nineteen adults who stutter participated in a 3-week intensive stuttering modification treatment program (the Successful Stuttering Management Program [SSMP]). A series of 14 fluency and affective-based measures were assessed before treatment, immediately after treatment, and 6 months after treatment. Measures included stuttering frequency; the Stuttering Severity Instrument for Children and Adults, Third Edition (SSI-3); a self-rating of stuttering severity; the Perceptions of Stuttering Inventory (PSI); the Locus of Control of Behavior Scale; the Beck Depression Inventory; the Multicomponent Anxiety Inventory IV (MCAI-IV); and the State-Trait Anxiety Inventory. Statistically significant improvements were observed on 4 of the total 14 measures immediately following treatment and on 4 measures at 6 months posttreatment. Statistically significant improvements observed immediately posttreatment included scores on the SSI and the Struggle, Avoidance, and Expectancy subscales of the PSI. Sustained statistically significant improvements at 6 months posttreatment were observed only on client-reported perceptions of stuttering (the Avoidance and Expectancy subscales of the PSI) and 2 specific affective functioning measures (the Psychic and Somatic Anxiety subscales of the MCAI-IV). The SSMP generated some anxiolytic effects but was ineffective in producing durable reductions of core stuttering behaviors, such as stuttering frequency and severity. The discussion focuses on the strengths, weaknesses, and durability of the SSMP treatment approach.

Measurement of stuttering in adults: comparison of stuttering-rate and severity-scaling methods

This study investigated the comparative reliability of 2 stuttering measurement tools when used by experienced judges: percentage of syllables stuttered (%SS) and a 9-point severity scale (SEV). The study also investigated the degree to which scores on 1 tool predict scores on the other and the distributions of stuttering when measured by these tools. Twelve experienced judges watched 3-min videotapes of 90 stuttering and 10 nonstuttering participants. Half the judges rated %SS, and half made severity ratings. Results showed very high intrajudge and interjudge agreement for both measures. There was a strong linear correlation between %SS scores and SEV scores. Based on this finding, it seems that the 2 measures can be regarded as largely interchangeable. The exception to this, however, was in cases where there was either a small number of significant fixed postures (blocks and prolongations) or a large number of innocuous repeated movements (repetitions) in the speech sample. In such cases, it appears that %SS and SEV scores combined would be needed to provide a valid measure of stuttering. SEV scores were more normally distributed than %SS scores, which were clearly skewed. The advantages and limitations of the SEV scale are discussed.