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Research Overview

General overview of projects

The mission of the Michael and Tami Lang Stuttering Institute is to help persons who stutter, family members of persons who stutter, and professionals who work with persons who stutter in the community through the provision and sharing of evidence based practices, the implementation of cutting edge clinical training methodologies, and the completion of innovative research with specific focus on translating theory to clinical practice. Our research efforts presently extend to four main areas of interest: exploration of potential causal contributors to the onset of childhood stuttering, improvement of assessment practices, enhancement of evidence-based treatment, and advancement of clinical training. View publications

Causal contributors

Although the etiology of stuttering remains unknown, there are data to suggest both motor and linguistic contributions to the difficulties persons who stutter have establishing and/or maintaining fluent speech1. A large majority of our past and present investigations of the etiology of stuttering has focused on the role of phonology. Other researchers have also contributed to our knowledge in this area; thus, in addition to citing our work, their work is also highlighted. Specifically, phonological encoding differences have been demonstrated in children and adults who stutter2. For example, young children who stutter do not appear to make the shift from holistic to incremental phonological encoding within the expected developmental timeframe3. Phonological disorders are the most frequent concomitant disorder with developmental stuttering4. Researchers have also posited that the phonological representations of children who stutter may be less specified5. In addition, researchers have suggested that the phonological encoding of adults who stutter may be uniquely compromised by increased cognitive demands6. These differences are not limited to overt speech tasks as less rapid and less accurate phonological encoding have also been demonstrated in adults who stutter using nonverbal speech tasks7. More recently, researchers have found the more complex the phonological representation, the more difficult it is for the persons who stutters to retain the word8. Taken together, our findings as well as findings of other researchers suggest additional exploration regarding the potential contributions of phonological working memory to difficulties persons who stutter have establishing and/or maintaining fluent speech is warranted9. Presently, we are actively exploring phonological working memory in a variety of innovative ways. To learn more about these projects either as a student researcher, potential participant or parent of a participant, please go to our Ways To Participate page.

Improvement of assessment practices

When completing a differential diagnosis of stuttering, the speech output of the child and/or adult requires careful analysis and consideration. However, our research suggests that any decision made with respect to the presence or absence of stuttering cannot be based solely on a systematic observation of their speech as this may lead to false positive and/or false negative diagnoses. The need for multiple and contextually diverse samples is supported by our research that has demonstrated that disfluency frequency often varies, sometimes markedly, depending on many factors including the articulatory rate10, communicative intent11, length and complexity of the utterance12, and nature of the sample13. For example, child initiated questions are more likely to result in stuttered speech than when they provide responses to questions14. We have also found that narration is more likely than structured conversation to elicit exemplars of school-age children’s stuttering-related behavior15. With additional research, we hope to clarify ways in which speech elicitation tasks can be modified to result in assessment tools that are maximally efficient as well as highly valid and reliable for use with both monolingual as well as bilingual speakers.

Researchers and clinicians alike have long debated cross-linguistic issues that may distinguish bilingual children who do and do not stutter from their monolingual fluent and dysfluent peers16. The recurring theme continues to be the critical need for empirically based reports of the speech disfluencies produced by bilinguals in each of their two languages17. At present, our knowledge of the manifestation of stuttering in bilingual children is limited to an alarmingly low number of single subject case studies18. If the growth trends reported in the 2010 census continue, within the next 50 years, 1 in 3 U.S. residents will be Hispanic and over 60% of our population will speak both Spanish and English19. Thus, the bilingual population that may be in immediate need of clinical understanding is bilingual Spanish English (SE) persons who stutter. Of further relevance to the differential diagnosis of stuttering in this unique clinical population is that bilingual SE speakers seem to produce mazes at higher rates than their monolingual peers20.

Mazes have been defined as disruptions in the forward flow of speech that are characterized by the production of a string of words, initial parts, or unattached fragments of words that do not in and of themselves contribute to the message that the person is attempting to communicate21. Stuttering has been defined as a disruption in the forward flow of speech that includes repetitions of sounds and syllables as well as audible and inaudible sound prolongations22. The apparent overlap in the types of disfluencies that are considered to be mazes and those that are typically defined as instances of stuttering23 along with the reported high rate of maze production in bilingual SE speakers as compared to monolinguals, raises the question, does bilingualism increase a bilingual SE child’s risk for development/persistence of stuttering or does bilingualism, perhaps, increase the risk for false positive identification of stuttering in the bilingual SE speaker? To be able to answer this question with reliability and validity, we first must increase our understanding of the typical speech disfluencies produced by bilingual SE speakers who do not stutter. We are actively exploring this complex question and have recently provided a few preliminary answers24.

What is particularly intriguing about our bilingual research efforts is that they may serve to alter the manner in which we classify stuttering behavior in monolinguals. We are presently exploring whether a shift away from types and frequency to quality may be more reliable and valid. Our preliminary data suggest the timing and tension of the speech disruption are the key distinguishing factors whereas the type and frequency of disfluencies overlap across fluent versus dysfluent speakers of one or more languages. To learn more about involvement in this line of research either as a student researcher, potential participant or parent of a participant, please go to our Ways To Participate page.

Enhancement of evidence-based treatment

With respect to the treatment provided through the Lang Stuttering Institute, some approaches have existed for years, other methods are either post-pilot stage or are under development for future piloting. Of those strategies that we employ that have historically and continue to be reported as best practice, many have little to no published data to support use. Part of our research efforts have focused on collecting the necessary data to support use. For example, for preschool children who stutter research suggests the Lidcombe Program, the Demands and Capacities Model and Parent Child Interaction therapy are effective. At the Lang Stuttering Institute, we treat each child and parent as an individual and adjust our protocol to meet their needs and factors critical to their daily communicative environment.  We focus on parent and child education, parent-child interaction styles, positive communication reinforcement across advanced speaking opportunities, and identification and modification of speech fluency. Parent and family involvement is critical and we incorporate both education and counseling into each session. We are also presently exploring the reliability and validity of various tools to assess treatment progress—these tools include client, parent as well as clinician based reports. We hope to identify measures of treatment progress that capture considerations beyond changes in overt speech behavior such as the impact of client motivation, meaningfulness/relevance of clinical activities, and self-perceived improvement.

In our treatment of older school age children and adults, we focus on modifying the moment of stuttering and we also focus on education, desensitization, and cognitive restructuring. The role of mindfulness therapy in stuttering treatment particularly with respect to preventing relapse and promoting long-term success of clinical outcomes is currently being explored at the Lang Stuttering Institute as well. In addition, similar to our efforts with pre-school children, we are collecting data regarding tools that are highly recommended for use but that have minimal data to support use. For example, voluntary stuttering (i.e., stuttering on purpose) is a technique that is commonly used in practice with clinical anecdotal data suggesting both behavioral and emotional benefits. In a recent study, we found that this tool is effective not simply from the perspective of the clinician but more importantly from the perspective of the client25. Self disclosure, wherein the person who stutters shares with the listener that he or she is a person who stutters, has been suggested to have both listener as well as speaker benefits. We are actively collecting data with respect to the impact of self-disclosure on listener perception and the impact on the person who stutters who employs this technique. We have expanded on past research efforts by including this self perspective and by exploring diverse listener perspectives as well as perception of school age children who do not stutter of the act of self disclosure by other school children who stutter. There are other commonly used strategies that we are presently exploring in order to provide or increase the evidence that exists to support use; to learn more about these strategies, please feel free to contact us through our Ways To Participate page.

Along with our dedication to exploring the effectiveness of commonly used treatment strategies, we are also dedicated to ensuring our treatment is reflective of the digital “coming of age.” To that end, we are exploring the role of social media, video blogs, and other forms of communication that are an integral part of the life of today’s client. We are developing a variety of Web tools to assist with transfer and maintenance of strategies initially learned within the clinic environment. We are also developing a variety of digital games that are aimed at engaging school age children in particular in order to best facilitate generalization of learned skills. In addition, we are piloting educational books and videos that can be used with both children and adults to complement our treatment goals. These materials will serve to further promote awareness and understanding of stuttering. We will make these Web Tools, digital games, and associated materials available as soon as we are able to do so. To learn more about the ongoing development and potential use/future access please feel free to contact us through our Ways To Participate page.

Advancement of clinical training

The lack of adequate academic and clinical training in stuttering, along with the reported consistent client dissatisfaction and subsequent decline in specialization, suggests the need for a means to expose students to the principles of evidence-based practice for stuttering at the earliest possible stage in their academic career. However, given the relatively few persons available who specialize in stuttering, a markedly high number of students will not have the opportunity to assess and/or treat persons who stutter until they are licensed Speech-Language Pathologists; thus, the substandard cycle of clinical practice for stuttering continues. We are developing clinical training modules that will allow graduate and undergraduate students with innovative, interactive opportunities to navigate best assessment and treatment practices within the classroom setting. In other words, we are developing tools to bridge the gap between the academic and clinical environment.

The prototype for our simulated program series has been used effectively, particularly in the training of physicians for whom the ability to relate to and counsel patients significantly impacts treatment outcomes. As opposed to complete submersion in a virtual environment which can be costly (e.g., $20,000 per headset) and limiting in the number of students who are able to have access, the use of a low tech simulated format will allow for the potential impact of our modules to be more far-reaching. Students will be provided the cutting edge opportunity to observe and interact with avatar clients who stutter in a simulated format in their classroom. They will sit in front of their personal computer with headphones and have the luxury of observing/making complicated clinical decisions. Perhaps, more importantly, through the use of our simulated training modules, students will have the opportunity to learn from their mistakes in the absence of client risk. To learn more about the development of these training tools either as a student researcher, potential participant or parent of a participant, please go to our Ways To Participate page.


Please know this page is intended to be a general overview only—there are many other past as well as present and future projects that are critical to our mission. If you are interested in learning more about our efforts, we encourage you to reach out to us. As noted in other locations on our website, it is our sincere hope that the research and clinical outcomes of the Michael and Tami Lang Stuttering Institute will further our understanding and treatment of childhood stuttering. We also hope that the our ongoing research efforts and the clinical training opportunities we are able to provide through the Lang Institute will significantly enhance clinician comfort and competency in working with this underserved population.