DEFINING THE SEVERITY OF STUTTERING 

By 

Angelica Bernabe Roman 

A THESIS 

Submitted to 
Michigan State University 
in partial fulfillment of the requirements   
for the degree of 

Communicative Sciences and Disorders – Master of Arts  

2024

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
ABSTRACT 

This study examined stuttering severity by reviewing 21 formal definitions from a 

comprehensive review of over 500 sources in English, Spanish, and Portuguese. While all 

definitions are primarily focused on observable characteristics, the study emphasizes the 

importance of considering the internal experience of stuttering, such as the speaker's sense of 

"loss of control.” Through an online survey, people who stutter, speech-language pathologists, 

and those who are both, were asked to define stuttering severity and explain the factors that 

influence it. Qualitative analysis of the definition of severity revealed five themes across all 

participants: disfluencies and visible physical tension, effective communication, affective, 

behavioral, and cognitive responses, adverse impact, and variability. People who stutter reported 

two additional themes: internal struggle and effort, and struggle may not be visible. Analysis of 

the factors that influence severity revealed seven themes: psychological factors, speech and 

language factors, situational factors, cultural factors, individual factors, speech therapy 

experiences, and perspectives and responses of the listeners. People who stutter reported an 

additional theme: force to produce speech. The results indicated that while speech speech-

language pathologists who do not stutter provided important insights that largely matched the 

perceptions of people who stutter, they did not identify the internal experience that people who 

stutter reported. This study advocates for incorporating both external observations and the 

subjective experience to better capture the complexity of stuttering severity, fostering a more 

comprehensive approach. 

 
 
 
 
ACKNOWLEDGEMENTS 

I would like to thank my mentor, Dr. J. Scott Yaruss, for his guidance and support in this 

study and since I met him in 2019 in Peru. His mentorship has taught me not only how to 

become a better clinician and researcher, but also how to be a better human being. His passion 

for our field and his ability to think innovatively have been a constant source of inspiration. 

Gracias, Scott. Thanks to my committee members Dr. Bridget Walsh, Dr. Seth Tichenor, and Dr. 

Jeff Searl for their time and feedback on this project. Their expertise and insights have enriched 

my research and I aspire to reach the same level of expertise as them one day.  

Agradezco profundamente el apoyo de mi familia, quienes han sido mi fortaleza y mi 

motivación para seguir adelante con mis metas en Estados Unidos y no rendirme. Les amo 

enormemente y les estoy infinitamente agradecida. Quiero mencionar especialmente a Antonella, 

mi pequeña. Espero que encuentre inspiración en mis logros y vea en ellos un ejemplo de 

perseverancia para alcanzar sus propias metas en el futuro. Te adoro más de lo que imaginas. 

Ook wil ik Jeroen bedanken voor zijn voortdurende steun. Want toen ik de steun het 

meest nodig had, zelfs op afstand, stond hij altijd voor me klaar. Ik lieg niet als ik zeg dat ik het 

zonder jou niet had kunnen doen. Ik hou van jou met heel mijn hart. Ik ben erg dankbaar voor de 

aanwezigheid van jou en je familie in mijn leven. Altijd. Bedankt. 

No puedo continuar sin agradecer a todos mis amigos latinos que me han apoyado en este 

proceso, a los que están aquí en Michigan y a aquellos en Perú y otros lados del mundo. Gracias 

por hacer mi vida mejor y más feliz. Espero con ansias verlos pronto nuevamente.  

Finally, I want to express my gratitude to all the participants of this study who completed 

the questionnaire in English, Spanish, and Portuguese. I have learned a lot from their insights, 

and I am really grateful for that. Thank you so much. Muchas gracias. Muito obrigada.

iii 

 
TABLE OF CONTENTS 

Introduction ..................................................................................................................................... 1 

Literature Review ............................................................................................................................ 4 

Method .......................................................................................................................................... 24 

Results ........................................................................................................................................... 31 

Discussion ..................................................................................................................................... 55 

Final Conclusions ......................................................................................................................... 63 

REFERENCES ............................................................................................................................. 64 

APPENDIX A: RECRUITMENT FLYERS ................................................................................ 73 

APPENDIX B: CONSENT FORM .............................................................................................. 75 

APPENDIX C: SURVEY QUESTIONS ...................................................................................... 77 

iv 

 
 
 
 
Introduction 

Although the “severity” of stuttering has long been measured, both in research and 

clinical practice, there are numerous problems associated with this measure. For instance, when 

asked to rate the severity of a given sample, different clinicians may arrive at different severity 

ratings (Cordes & Ingham, 1994; Hall et al., 1987; Hulit, 2004). Also, the level of severity 

perceived by the clinician could differ from the level of severity perceived by the person who 

stutters (Adriaensens et al., 2015; Aron, 1967; Manning & DiLollo, 2017; Moïse-Richard et al., 

2021; O’Brian et al., 2004). That is, a clinician may judge a speaker’s stuttering to be “mild,” 

while the speaker may judge that their stuttering is “severe”. 

One possible reason for these disagreements is a lack of consensus regarding the 

definition of stuttering severity. A review of historical and recent publications on stuttering 

reveals that nearly all resources address the concept of severity, but very few provide actual 

definitions of what is meant by severity. In fact, an extensive search of the literature revealed 

only a few instances in which formal definitions of stuttering severity were presented (see Table 

1). Even though those definitions are certainly relevant and meaningful as descriptors of 

stuttering, they nevertheless reflect different aspects of the stuttering experience. The majority of 

the definitions provided are based on the observable characteristics, that is, the features that a 

listener or conversational partner might be able to observe. As Tichenor and Yaruss (2019) 

explained, however, stuttering can be also viewed in terms of the perceptions that speakers 

themselves experience internally. One way to experience this has been defined as a “loss of 

control” that a person experiences while speaking, and this internal experience may not always 

be perceived by other people. For example, a person might sense that a moment of stuttering is 

occurring or about to occur, but in order to hide their stuttering so that it is not noticeable to the 

1 

 
 
 
listener, they may stop talking or change the word that they say. In that case, the observer might 

not recognize that stuttering occurred even though the speaker would indicate that they stuttered.  

Inconsistencies and uncertainties about the definition of stuttering severity are relevant 

because the concept is ubiquitous in both clinical settings and research settings. Clinically, 

severity is judged by speech-language pathologists in assessing, diagnosing, and treating the 

condition. Numerous assessment tools have been created for measuring stuttering severity, and 

many treatment approaches are focused on reducing the outwardly apparent severity of 

stuttering, whether directly or indirectly (Franken & Laroes, 2021; Kelman & Nicholas, 2020; 

Onslow et al., 2023). Moreover, countless publications and books explain how clinicians should 

work to reduce severity (De Sonneville-Koedoot, Stolk, et al., 2015; Fraser, 2010; Rickheit & 

Strohner, 2008; Rohani Ravari et al., 2022; Tarkowski, 2016; Williams, 2023). Still, most of 

these authorities do not define what is meant by severity.  

In research, severity is measured for selecting participant samples, describing, and setting 

inclusion/exclusion criteria, differentiating subgroups of participants, measuring the effects of 

various interventions, and comparing results in longitudinal studies. For example, the 

participants may need to exhibit a minimum percentage of stuttered syllables or level of severity 

in order to participate in a study (Buzzeti et al., 2016; Carrasco et al., 2015; Costa et al., 2019; 

Fiorin et al., 2015; Juste et al., 2016; Neumann et al., 2005; Nogueira et al., 2015; Regacone et 

al., 2015; Ritto et al., 2015). Stuttering severity is also used to differentiate control and 

experimental groups (Andrade, 2010; Pirinen et al., 2023; Rossi et al., 2014); it is commonly 

used as a dependent or independent variable (Abdul Waheed et al., 2022; Adriaensens et al., 

2015); and in comparison over the time (De Sonneville-Koedoot et al., 2015). Nevertheless, the 

vast majority of research has not actually defined what severity is.  

2 

 
 
 
There is a clear gap in the literature with respect to the definition of the severity of 

stuttering, and this gap has consequences for both clinical and research endeavors. For that 

reason, this study aimed to specify the definition of stuttering, while accounting for the 

perspectives of both listeners (clinicians and researchers) and people who stutter. 

3 

 
 
 
 
 
Definitions of stuttering severity 

Literature Review 

The first part of this study examined definitions of stuttering severity. Inclusion criteria 

involved searching sources that were published on peer-reviewed articles, books, and thesis, in 

English, Spanish, and Portuguese. The literature review was conducted in multiple languages to 

access information that may not be present in the English-language literature, and to ensure an 

understanding of the topic from diverse cultural perspectives. This examination included the 

terms “severity,” “severe,” “stuttering,” “stammering,” “disfluency,” “dysfluency,” “severidad,” 

“gravedad,” “severo,” “tartamudez,” “disfemia,” “disfluencia,” “severidade,” “gravidade,” 

“gagueira,” “gaguez,” anywhere in the text. In other words, all the sources that used the concept 

of severity in relation to stuttering were examined, with no additional filters based on the 

content. Those terms were located through a search of the Michigan State University Library 

system (which searches 1249 databases), as well as PubMed, the ASHA Wire, Biblioteca de la 

Pontificia Universidad Católica del Peru, Google Scholar, and SciELO. Based on the extensive 

literature review of more than 500 sources, 21 formal definitions of severity in the context of 

stuttering were found: 19 in English, 1 in Spanish, and 1 in Portuguese. Table 1 summarizes the 

definitions from these various publications.  

4 

 
 
 
 
 
 
 
 
 
Table 1. Definitions of stuttering severity 

Definitions of stuttering severity 

Authors and year 

Definitions 

Spurlock (1966, p. 1) 

“Severity is a way of quantifying the 

extent of abnormality or degree of 

interference with the normal speech 

process. To say that one stutterer is more 

severe than another is to say that he 

appears to be more abnormal than the 

other” 

Young (1970, p. 300) 

 “Stuttering severity is a perceptual 

dimension measured by processing 

judgments extracted from observers” 

Conture (1990, p. 2) 

“Severity of stuttering refers to the 

subjective, rather holistic, judgment of 

the degree of stuttering exhibited by a 

stutterer, usually expressed in terms of 

mild, moderate or severe and relates to 

the stutterer’s problem as a whole but can 

also be applied to separate instances of 

stuttering (cf. Sherman & McDermott, 

1958)” 

Kell et al. (2009, p. 2749) 

“Stuttering severity was defined as the 

percentage of stuttered syllables 

according to the guidelines by Boberg & 

Kully (1994)” 

Kuniszyk-Jozkowiak (1995, p. 14)  

“Stuttering severity defined as the 

number of errors characteristic of 

stuttering, such as: repetitions, insertions, 

blockades etc. per 100 syllables” 

5 

 
 
 
 
 
 
 
 
Table 1 (cont’d) 

Shapiro (1999, p. 14) 

“Severity of stuttering is a judgment 

based on objective measurement of the 

degree of stuttering demonstrated by a 

person who stutters” 

Ruscello (2001, p. 174) 

“Based on the work of Martin et al. 

(1984) perceived severity of stuttering is 

a rating of ‘natural and unnatural’ speech 

to the degree of deviancy”  

Zebrowski & Kelly (2002, p. 16) 

“Severity of stuttering is a global 

judgment based on listener’s perceptions 

of the frequency, type, and duration of 

disfluent speech, as well as the presence 

or absence of associated behaviors”  

Klassen (2002, p. 98) 

“Severity is the seriousness of the 

stuttering, including its length, and 

behaviors such as avoiding eye contact, 

grimaces, etc.” 

Neumann et al. (2003, p. 191) 

Stuttering severity was defined by 

subjects’ percentage of disfluent syllables 

in four speaking situations (talking with 

the therapist; overt reading; making a 

tele-phone call to an unknown person; 

interviewing people on the street). 

Giraud et al. (2008, p. 191) 

“Stuttering severity was defined as the 

percentage of stuttered syllables in four 

different speaking situations (speaking to 

a therapist, reading, phoning, speaking to 

a passer-by”) 

6 

 
 
 
 
 
 
 
 
 
Table 1 (cont’d) 

Correa (2010, p. 204) 

“Stuttering severity, that is, the degree of 

difficulty in temporal motor control of 

speech (…) To determine the degree of 

severity of the participants' stuttering, a 

scale was used whose score is divided 

into four components (Yairi & Ambrose, 

1999; Jakubovicz, 1997): frequency and 

duration of disfluencies, tension and 

secondary behaviours” 

“Severidade da gagueira, ou seja, ou grau 

de dificuldade do controle motor 

temporal da fala (…) Para determinar o 

grau de severidade da gagueira dos 

participantes foi utilizada escala cuja 

pontuação divide-se em quatro 

componentes (Yairi e Ambrose, 1999; 

Jakubovicz, 1997): frequência e duração 

das disfluências, tensão e fenômenos 

secundários” 

Shapiro (2011, p. 11) 

“Severity of stuttering refers to the degree 

of stuttering demonstrated by a person 

who stutters”  

O’Brian et al. (2011, p. 88) 

“Typical stuttering severity was defined 

as the severity of your speech for the 

majority of the day”  

7 

 
 
 
 
  
 
 
 
 
 
 
 
 
Table 1 (cont’d) 

Pertijs et al. (2014, p. 164) 

“Stuttering severity is a measure based on 

the objective measurement of stuttering 

behaviour, such as stuttering frequency, 

duration of stutter moments, the type of 

dysfluencies and secondary behaviours” 

Boyle (2015, p. 4) 

 “The disruption in your speech that you 

think is noticeable on the surface for the 

majority of the day. It does not refer to 

the impact of the disorder as a whole on 

your life” 

Neumann et al. (2018, p. 122) 

“Stuttering severity, defined as 

Berrospi et al. (2018, p. 27) 

"Degree to which speech is affected (...) 

percentage of stuttered syllables (%SS)” 

the degree of severity is determined 

according to the percentage of stuttered 

syllables in their verbal communication, 

according to Salgado (2008)" 

“Grado en que se ve afectada el habla 

(…) el grado de severidad se determina 

según el porcentaje de sílabas 

tartamudeadas en su comunicación 

verbal, según Salgado (2008)” 

Guitar (2019, p. 156) 

“Severity: generally, a measure of the 

impediment to communication caused by 

the stuttering. This may be an overall 

impression or a compilation of stuttering 

frequency and duration as well as other 

behaviors that impede communication.” 

8 

 
 
 
 
 
 
 
 
 
 
 
Table 1 (cont’d) 

Yairi & Seery (2021, p. 194) 

“The level of disruption in the delivery of 

continuous speech” 

Zebrowski et al. (2022, p. 4) 

“Is the description of the degree to which 

stuttering interferes with typical 

speaking/communication. The degree of 

severity ranges from not very serious 

(i.e., mild) to quite serious (i.e., severe). 

Specifically, stuttering severity is often 

indexed by an overall or composite score 

that may be based on several measures. 

For example, the Stuttering Severity 

Instrument, fourth edition (SSI-

4) determines stuttering severity by 

considering the following measures: 

(1) frequency of instances of stuttering 

(stuttered disfluencies), (2) the 

average duration of the three longest 

instances of stuttering, and (3) 

the quantity and quality of associated 

nonspeech behaviors (see the explanation 

later)” 

These cited definitions have long been used by researchers and clinicians to form part of 

their theoretical framework and treatment practices. Even though these definitions include 

important aspects of the stuttering experience, two main issues arise. First, these definitions 

reveal a lack of consensus on how the severity of stuttering should be defined. Some define 

severity as a measure of frequency and duration, others as the level of disruption, while others 

define severity as the degree of natural or unnatural speech, and still others define stuttering 

9 

 
 
 
 
 
 
severity based on different factors. These differences in definition are problematic because the 

absence of a consensus may negatively affect both treatment and research. For example, research 

has shown that when speech-language pathologists need to determine a severity rating after 

analyzing the same recording of a person's speech, there may be differences in the results they 

obtain (Cordes & Ingham, 1994; Hall et al., 1987; Hulit, 2004), which could be influenced 

because there is not an agreement on what is stuttering severity and what exactly they are 

assessing. Additionally, in research, it is challenging to interpret, replicate, and compare results if 

there is no standard definition. For that reason, there is a need for a consensus on the definition to 

develop accurate research and effective intervention.  

The second problem with the existing definitions of stuttering severity is that most are 

primarily focused on characteristics that a listener might perceive, such as the number of 

disfluencies and physical movements, but not on the internal experience of stuttering. There is a 

common tendency to take for granted that certain types of observable disfluencies and stuttering 

are the same thing; however, stuttering encompasses much more than just what observers can 

notice about the way people talk (Johnson et al., 1963). When people stutter, speakers have 

reported to have “a feeling” inside them (Emerick & Hamre, 1972), which was described by 

Perkins (1990) as a sense of “loss of control” while speaking (see also Tichenor and Yaruss, 

2019). 

What listeners observe is not the feeling of losing control. Instead, they observe the 

physical reactions as a person tries to regain control and continue to speak. In that regard, the 

severity of the overt characteristics of stuttering as commonly defined fails to capture the essence 

of stuttering, that internal essence that can be ultimately judged by the person who stutters (Alm, 

1997; Tichenor & Yaruss, 2019). 

10 

 
 
 
Assessment of stuttering severity 

Severity is a concept used by most clinicians in the assessment of stuttering, because it 

allows them to have quantitative data, it can help to establish the effectiveness of treatment, and 

it is used to determinate if a person’s speech meet the diagnostic criteria for stuttering (Eve et al., 

1995; Guitar, 2019). Current ways to assess stuttering severity can be divided into two 

approaches: assessments from the clinician’s perspective and assessments from the person who 

stutters perspective. The first one asks the clinicians to rate severity according to the way they 

observe the person who stutters, while the second one asks the person who stutters to assess their 

own severity.  

Other measures that may be relevant to the speaker’s experience is the impact of 

stuttering in their lives, which has been examined in the Wright & Ayre Stuttering Self-Rating 

Profile (WASSP; Wright & Ayre, 2000), and the Overall Assessment of the Speaker’s 

Experience of Stuttering (OASES; Yaruss & Quesal, 2006). Those assessments do not provide a 

stuttering severity measure. Instead, they are focused on the impact of stuttering in the life of the 

person who stutters. For this study, the authors are focused on severity, so measures of impact 

are not further discussed. 

Assessment of severity from the perspective of the clinician 

Numerous assessments have been created for measuring stuttering severity. Among the 

first severity measures described in the stuttering literature was the Iowa Scale of Severity of 

Stuttering (Lewis & Sherman, 1951). This scale goes from zero to seven, where the number zero 

indicates no stuttering and seven indicates the most severe stuttering (Sherman, 1952; Spurlock, 

1966). It asks the observer (clinician, clinical student, mother, father, etc.) to describe and 

analyze the sample(s) of speech and the situation in which the rating was made. It considers the 

11 

 
 
 
amount of stuttering and tension, the duration of disfluencies, the patterns of disfluencies, and 

the number of stuttering-associated body movements (Johnson et al., 1963).  

Current measures include the Test of Childhood Stuttering (TOCS) by Gillam et al. 

(2009), and the widely known Stuttering Severity Instrument, 4th edition(SSI-4) by Riley (2009). 

The TOCS (Gillam et al., 2009) is an assessment that evaluates the fluency and stuttering 

behaviors of children ages 4 to 12 years. To assess severity, the clinician asks the child to 

complete four speech fluency tasks: name 40 pictures as quickly as possible, produce sentences 

with the same syntactic structure as the clinician, answer questions about pictures, and tell a 

story that corresponds to the pictures presented. For each of the four speech fluency tasks, 

clinicians obtain a raw score, which matches a scale from Typical Fluency to Severe Disfluency. 

The TOCS also includes The Observational Rating Scale, which is a sheet completed by the 

clinician, teachers, parents, or caregivers. In this scale, the adult is asked to think about the 

child’s speech in the last two months, read the statements provided, and rate from 0 to 3, where 0 

is never and 3 is often. It is divided into two: the Speech Fluency Rating Scale and the 

Disfluency-Related Consequences Rating Scale. The first scale assesses the occurrence of 

repetitions and duration of stuttering events, among others. For that scale, scores will match a 

severity ranking from Typical Fluency to Severe Disfluency. The second scale, the Disfluency-

Related Consequences Rating Scale, assesses tension and body moments while speaking. Scores 

on that scale will cores from 0 to 6 are considered Typical Consequences, and above 6 are 

considered Greater Than Typical Consequences. Additionally, clinicians can analyze the speech 

rate, disfluency duration, associated behaviors, stuttering frequency, and speech naturalness. 

Clinicians are suggested to use this data to describe the pretreatment status, assess changes over 

12 

 
 
 
time, and identify specific goals for intervention, such as reducing the frequency of stuttering or 

the associated behaviors.  

The SSI-4 is a norm-reference stuttering assessment for children and adults that is used 

for clinical and research purposes (Riley, 2009). It measures the frequency of stuttering events, 

the duration, and the physical behaviors. It asks the clinician to record speech samples from an 

in-depth interview with the person who stutters, direct observation of the person’s speech, and 

reading tasks, depending on the age of the child. The instructions for the SSI-4 recommend 

getting speech samples beyond the clinic, which could be at home, at work, at school, or on the 

telephone. Once the clinicians obtain the speech samples, they evaluate the frequency, duration, 

and physical movements. The frequency is the percentage of stuttered syllables, which is 

obtained by counting the total number of syllables and stuttered syllables, or by using the 

Computerized Scoring of Stuttering Severity that comes in the assessment. The value obtained 

matches a task score from 2 to 18. To assess duration, the clinician is asked to measure the length 

of the three longest stuttering events. The number of seconds obtained matches a scale score 

from 2 to 18. Videotapes are considered useful for getting information about physical behaviors, 

such as facial, head, or extremities movements. Those movements are scored from 0 to 5, where 

0 is None and 5 is “Severe and Painful Looking.” The values of each of the three areas are added 

together to generate a total overall score. The number obtained match a severity equivalent, 

which could be Very Mild, Mild, Moderate, Severe, or Very Severe.  

Although the Iowa Scale of Severity of Stuttering, the TOCS, and the SSI-4, are among 

the most common assessments designed to measure the severity of stuttering, none actually 

defines what severity is. Additionally, all are focused on the observable characteristics of 

13 

 
 
 
stuttering behaviors, and not on what constitutes stuttering from the perspective of the speaker, 

which may be the feeling of losing control.  

There are numerous problems with assessing only or primarily observable characteristics 

of stuttering. For example, stuttering can occur without easily detectable overt characteristics 

(Naylor, 1953), due to tricks and distractions that the person who stutters can use to hide 

stuttering (Constantino et al., 2017). These strategies render the stuttering behavior “covert” – 

that is, the speaker may successfully hide the moments of stuttering by changing the words, 

pretending to forget what they were saying, or staying in silence (Douglass et al., 2019). Even 

though people might not notice a moment of stuttering due to these covert strategies, speakers 

may still experience negative impact, including feelings of anxiety and depression (Sønsterud et 

al., 2022). Thus, though the number of overt characteristics of stuttering may be minimal, the 

real severity and impact of stuttering may be high (Douglass et al., 2019). Another concern with 

assessments that focus only on surface behaviors is that a potential client may not achieve the 

“requirements” to be diagnosed as stuttering, even though they experience the sensation of losing 

control in their speech.  

Research has also shown that people who stutter may experience physical movements or 

tension that are not easily visible to clinicians. Tichenor et al. (2017) conducted a study in which 

10 adults who stutter and two board-certified specialists in stuttering evaluated two speaking 

samples of each adult using the SSI-4. In all cases, the degree of tension reported by the speakers 

who stutter was higher than that observed by the expert clinicians. In part, this occurred because 

the speakers experienced tension in parts of the body that clinicians could not identify, such as 

the chest, abdomen, and throat. As it is possible to observe, a stuttering severity assessment that 

14 

 
 
 
is based solely on the clinician's perspective may not be entirely valid, potentially affecting the 

correct diagnosis and treatment. 

Assessment of severity from the perspective of the person who stutters 

Clinicians have also developed severity ratings based on the self-reports of people who 

stutter. Those questions are considered important to provide sample behaviors and to assess the 

person's perspective of their stuttering (Manning & DiLollo, 2017). Different ways to self-assess 

the severity of stuttering have been developed over the years. The first studies on this topic were 

in the 90s by Naylor and Aron. Naylor (1953) conducted a study in which 24 adults who stutter 

were trained to use a 9-point severity rating scale, from 1 (least severe stuttering) to 9 (most 

severe stuttering), in a recorded reading task (63 seconds). Similarly, Aron (1967) asked 46 

adults who stutter to complete a reading task and then rate themselves on a 9-point scale, from 1 

(no stuttering) to 9 (very severe stuttering), in terms on visible behaviors. They rated their 

severity immediately after the reading and 30 minutes later, by listening to the audiotape.  

Current ways to assess self-severity are similar. For example, O’Brian et al. (2004) used a 

Self-Rating Stuttering Severity Scale as a clinical tool with 10 people who stutter. The 10 

participants made a 5-minute audio recording of themselves speaking in 6 different scenarios. 

They had to rate themselves for each situation, on a scale from 1 to 9, where 1 meant No 

stuttering and 9 Extremely severe stuttering.  

Another assessment is the Subjective Screening of Stuttering (SSS), which is a self-report 

measure developed by Riley et al. (2004). This assessment has 3 areas: perceived stuttering 

severity, level of internal or external locus of control, and reported word or situation avoidance. 

It includes 8 questions to be answered on a 1 to 9 scale. For the first area, Perceived stuttering 

severity, people who stutter has to answer how would they score their speech during the session, 

15 

 
 
 
and how would they score their speech with close friends, authority figures, and on the 

telephone, all during the last week. For those questions, 1 is equivalent to “relative relatively 

fluent” and 9 to “severe stuttering.”  

Overall, self-severity ratings have been considered a useful clinical tool because they 

complement the traditional stuttering severity measures provided by the speech pathologist 

(O’Brian et al., 2004). However, there are two main problems with these measures. The first one 

is that these ratings, even though they are from the perspective of people who stutter, are also 

primarily based on the observable characteristics of stuttering. They do not consider the sense of 

losing control while speaking, and they have been more used as a secondary tool to validate the 

overt measures realized by clinicians (Guntupalli et al., 2006). The second problem is that these 

self-ratings of stuttering severity also have not defined what is meant by severity. In other words, 

the field does not have an agreement on what is meant by the severity of stuttering for speech-

language pathologists, and we do not know what the severity of stuttering is for people who 

stutter. 

Treatment of stuttering severity 

The severity of stuttering has been used widely as a primary outcome measure in different 

treatment approaches, through assessments like the SSI-4 or self-reports (Andrews & Ingham, 

1971; Blomgren et al., 2005). Current stuttering therapy programs that rely on various types of 

severity measures include the Camperdown Program, the Lidcombe Program, the Palin Parent-

Child Interaction Therapy Approach, and the Restart-DCM Program, among others.  

Therapy programs directly focused on reducing stuttering severity 

The Camperdown Program is a behavioral treatment for people who stutter older than 12 

years old, by O’Brian et al. (2018), which has a pre-defined goal of achieving a stuttering 

16 

 
 
 
severity rating of 0. This approach uses the Stuttering Severity Scale, a scale used to quantify 

overt stuttering behaviors from 0 to 8, where 0 is no stuttering and 8 is extremely severe. The 

purpose of this scale is to collect measures during the day-to-day talking and compare severity 

during and after treatment. In the session, the clinician engages in a recorded conversation with 

the client, they listen to the recording together and immediately assign a stuttering severity score. 

Differences between the clinician’s and client’s scores are discussed in order for the clinician to 

understand how clients view their speech. During the first weeks, the procedure of obtaining the 

severity is repeated until there is agreement between the client and the clinicians, defined as 

having no differences of more than one point on the scale value. The number obtained in the 

Stuttering Severity Scale is assigned to a rating, where a score of 1 is extremely mild, 2-3 is 

considered mild, 4-5 is considered moderate, 6-7 is considered severe, and 8 is considered 

extremely severe. Clients are expected to continue with the program until they achieve a severity 

score of 0-1. Thereafter, they move on to generalization activities, in which they are expected to 

maintain the 0-1 severity score by practicing in controlled speaking activities and everyday 

conversations, without avoiding situations and while using fluency techniques. After that, the 

frequency of therapy is reduced progressively, and the client is discharged when they have the 

skills to monitor their speech, and control stuttering and it is variability while maintaining a 

stuttering severity score of 0 to 1.  

Another program directly focused on reducing the severity of stuttering is the Lidcombe 

Program. This is a behavioral treatment for children who stutter under the age of 6, and, in some 

cases, for older children (Onslow et al., 2023). In this program, parents and clinicians use a 

Severity Rating Scale from 0 to 10, where 0 is no stuttering, 1 is extremely mild stuttering, and 

10 is extremely severe stuttering. The procedure of obtaining the severity is repeated until there 

17 

 
 
 
is an agreement between the parents and the clinicians, defined as having no differences of more 

than one scale value. Parents are asked to rate the severity of their child every day, either as one 

number that represents the whole day, or including speaking situations such as talking at dinner 

or in public settings. The goals of the program are twofold: the child to not stutter or almost not 

stutter, and to be able to maintain it for a long time (O’Brian et al., 2013; Subasi et al., 2022). To 

assess that severity, parents should keep using the Severity Rating Scale for over a year. If the 

severity of stuttering increases, then the family is supposed to contact the clinician to manage 

stuttering again (Onslow et al., 2023). 

Both the Camperdown Program and the Lidcombe Program have a primary goal of 

reducing the severity of observable stuttering behavior, which is assessed through severity rating 

scales. Even though both approaches have research that supports their effectiveness in reducing 

severity (Carey et al., 2010, 2012; Cocomazzo et al., 2012; Hearne et al., 2008; O’Brian et al., 

2003, 2008, 2013, 2023; Rohani Ravari et al., 2022; Subasi et al., 2022), there are important 

aspects to highlight regarding how severity is approached. First, severity has been described in 

terms of frequency and physical movements, but severity itself has not been defined. This means 

that there are descriptions of how stuttering can occur, and the notion of stuttering severity is 

recognized, but there is no specific definition of what exactly severity is. This reinforces the fact 

that there is a need to define the severity of stuttering. Second, even though stuttering severity is 

assessed by people who stutter, as the authors recognized, that severity is assessed and treated in 

terms of the overt stuttering behaviors, and not the internal experience of feeling out of control. 

This is problematic because, as has been mentioned above, stuttering is an internal experience 

that not always can be seen. In that regard, it is possible to conclude that emphasizing in the 

overt characteristics rather than the internal experience could give the message that it is more 

18 

 
 
 
important how stuttering looks for others than how it feels for the person who stutters. It is also 

true that there is no research that focuses on how to treat stuttering having as the core the sense 

of loss of control while speaking, neither for children nor adults. For that reason, future research 

should also study how to treat the severity from the person who stutters’ inner experience of loss 

of control. 

Therapy programs less focused on reducing stuttering severity  

The Rotterdam Evaluation Study of Stuttering Therapy Randomized Trial – Demands and 

Capacities Model (RESTART – DCM) is a treatment program for preschool children who stutter, 

ages 2 to 6 (Franken & Laroes, 2021). During the assessment, this program uses the SSI-4 to 

determine the severity of the child. Additionally, clinicians gather information regarding the 

perceived severity and burden of stuttering, through a visual analogue rating scale (VAS -score). 

During treatment, parents are asked to start a logbook, in which they track the severity using the 

scale that is part of the Lidcombe Program, or the 8-point scale of Yairi and Ambrose (1999), 

where 0 is normal and 7 is very severe. Parents can score severity daily or use a score for the 

entire past week. The severity obtained helps the clinician decide if the child should target 

speech more directly, with the expectation that the child spontaneously changes their speech 

behavior due to the exercises worked in therapy. However, fluency in speech is not the main 

goal. This program also teaches the child that stuttering is okay and work towards having 

positive attitudes regarding communication.   

Another approach that is less focused on reducing stuttering severity is the Palin Parent-

Child Interaction Therapy for Early Childhood Stammering (Palin PCI), for children before 7 

years old (Kelman & Nicholas, 2020). This approach assesses stuttering behaviors, with the goal 

of establishing severity through the analysis of a video-recorded speech sample. The clinician 

19 

 
 
 
obtains information about the percentage of stuttering syllables, duration, number of repetitions, 

tension, avoidance behaviors, physical movements, and rate of speech. In order to do this, it is 

recommended to use standardized assessments such as the SSI-4 (Riley, 2009) or TOCS (Gillam 

et al., 2009) explained in previous sections. In case other clinicians do not have access to these 

measures, a subjective assessment is suggested to determine if the child’s stuttering is 

categorized as mild, moderate, or severe. This subjective assessment should be based on the 

frequency of stuttering, the type of stuttering, and the quantity of physical struggle and tension 

related to stuttering. This approach also uses the Palin Parent Rating Scale (Palin PRS) by 

Millard and Davis (2016). This is a 19-item questionnaire that provides the clinician with 

information regarding the parent’s perspective of the stuttering severity, their current knowledge, 

their confidence on how to support their kid, and the impact of stuttering on the child and them. 

Section 2 of the questionnaire is called “The severity of stuttering and parent concern”. It asks 

seven questions, four related to stuttering severity and three to parent concerns, to be answered 

on a 0-10 scale. Numbers close to 10 reflect the best scenario for the family. Stuttering severity 

is reassessed during treatment to assess progress. However, it is not the most important factor in 

therapy. As the authors explain, the goal is for the child and the family to understand that it is 

okay to stutter. They promote being open and talk about stuttering, build confidence, desensitize, 

and work with thoughts and emotions.  

Both RESTART – DCM and Palin PCI are approaches with scientific evidence (De 

Sonneville-Koedoot et al., 2015; De Sonneville-Koedoot, Adams, et al., 2015; De Sonneville-

Koedoot, Stolk, et al., 2015; Millard et al., 2009, 2018; Millard & Davis, 2016; Onslow & Lowe, 

2019), which uses stuttering severity as a part of their assessment and treatment. However, they 

do not account for severity as the main factor in therapy. In similar ways, both agree that there is 

20 

 
 
 
nothing wrong with stuttering and state that clinicians should prioritize communication attitudes. 

Nevertheless, even though stuttering severity is not the main goal of treatment, it is important to 

mention that when it is assessed and treated, it is in terms of what is observable. For preschool 

children, clinicians may prefer this because many times children in that range of age are not 

aware of stuttering, and in those who are, clinicians try to include their perspectives by asking 

them questions related to their speech, such as if they feel tension and where they feel it. 

However, it is considered that with a clear definition of the severity of stuttering and which 

dimensions constitute and influence severity, clinicians would be able to improve and get more 

precise information, which will allow them to enhance assessment and therapy.  

Uses of stuttering severity in research 

The severity of stuttering has been used in stuttering research for several purposes. 

Researchers have used this term as an inclusion or exclusion criteria, to differentiate subgroups 

of participants, to measure the effects of different interventions, and to compare interventions in 

longitudinal studies. For instance, the participants needed to have a minimum percentage of 

stuttered syllables or level of severity in order to participate in the study, using assessment tools 

like the SSI-4 (Buzzeti et al., 2016; Carrasco et al., 2015; Costa et al., 2019; Fiorin et al., 2015; 

Juste et al., 2016; Neumann et al., 2005; Nogueira et al., 2015; Oliveira et al., 2014; Regacone et 

al., 2015; Ritto et al., 2015).  

Stuttering severity is also used to differentiate control and experimental groups (Andrade, 

2010; Pirinen et al., 2023; Rossi et al., 2014); as a dependent or independent variable (Abdul 

Waheed et al., 2022; Adriaensens et al., 2015; Picoloto et al., 2017); and to compare treatment 

approaches over the time (De Sonneville-Koedoot et al., 2015). However, the vast majority of 

research has not defined what severity is. 

21 

 
 
 
One study that did define severity was conducted by Boyle (2015). This study examined 

the relationship of social support, empowerment, self-help support group participation, and group 

identification on the quality of life in adults who stutter. Measures included demographic and 

stuttering-related parameters, which included a self-rating severity. This self-rating was assessed 

through a 9-point Likert scale in eight different conversational situations, where a high score 

indicated more severe physical stuttering. For this study, participants were provided with the 

following definition of stuttering severity: “the disruption in your speech that you think is 

noticeable on the surface for the majority of the day. It does not refer to the impact of the 

disorder as a whole on your life”. The goal of providing a definition was to ensure that the 

participants received a similar concept of what the author meant by severity and to reduce the 

potential overlap between the severity perceived and other psychological scales.  

Even though some authors have defined severity and their studies provide us with 

valuable information to understand the stuttering experience, similar issues as mentioned in the 

previous section arise: there is no consensus on the definition of stuttering severity in research, 

and all the definitions are from the listener’s perspectives. In that regard, it is considered that 

researchers would benefit more if they assessed the severity of stuttering in a broader way than 

just what is observable. For example, it could be concluded that excluding participants who do 

not reach a number of stuttering events established to participate in the study could impact the 

results because it excludes the experiences of another important group of people who stutter. 

Additionally, it may be feasible to infer that research that has as a goal to assess the efficacy of a 

treatment approach, having as a factor for success the reduction of the severity after therapy, in 

terms of what is observable, could perpetuate and reinforce the idea that it is better to hide 

22 

 
 
 
stuttering moments from others, even if that unintentionally lead people who stutter to stutter 

covertly in order to reach those standards.  

Finally, it is important to highlight that the literature review revealed an absence of 

studies that look into defining stuttering severity. As a response to this gap in research, this study 

is focused on understanding this concept from a variety of perspectives. 

Summary and Study Aim 

Stuttering severity is a term used widely in stuttering assessment, treatment, and research. 

However, an extensive literature review demonstrated that there have been just a few instances in 

which it has been clearly defined. Additionally, those definitions reveal a lack of consensus on 

what is meant by severity, and the majority of them are based on the observable characteristics of 

stuttering, such as frequency and body movements. Nevertheless, stuttering is an internal 

experience that can be described as a sense of loss of control while speaking that only sometimes 

can be perceived by others. If a person changes the word or avoids talking, the others will not 

notice a stuttering moment, even though the person could affirm that it occurred.  

The purpose of this study is to define stuttering severity taking into account the 

perspectives of both people who stutter and professionals. It is considered that by incorporating 

the perspectives of people who stutter the field gains a deeper understanding of severity, while 

the perspectives of professionals ensure that it is used in terms of evidence-based practice.  

23 

 
 
 
 
 
Method 

The first part of this study included a literature review of peer-reviewed articles, books, 

and thesis, in English, Spanish, and Portuguese, to find and examine definitions of stuttering 

severity. The terms searched included “severity,” “severe,” “stuttering,” “stammering,” 

“disfluency,” “dysfluency,” “severidad,” “gravedad,” “severo,” “tartamudez,” “disfemia,” 

“disfluencia,” “severidade,” “gravidade,” “gagueira,” “gaguez,” anywhere in the text. After an 

extensive review, 21 formal definitions of stuttering severity were found: 19 in English, 1 in 

Spanish, and 1 in Portuguese. Table 1 in the literature review section summarizes the definitions 

from these various publications.  

The lack of definitions and consensus led to the second part of this study, creating a 

questionnaire to gather information on perspectives of the severity of stuttering. In order to do 

that, the study included two groups of participants: adults who stutter and speech-language 

pathologists. The first group included adults who currently or have ever considered themselves to 

stutter. The second group included speech-language pathologists who currently or ever have had 

clients who stutter in their caseload. There was an option to indicate if a participant is both a 

person who stutters and a speech-language pathologist. 

Inclusion criteria for both groups also included being over 18 years old and speaking 

English, Spanish, and/or Portuguese. Participants were recruited from December 2023 to January 

2024, using snowball and convenience sampling, through personal contacts of the authors, and 

flyers posted on the social media accounts of stuttering organizations and stuttering centers 

globally (Appendix A).  

Participants completed a Qualtrics survey through the website of the Michigan State 

University Spartan Stuttering Laboratory. It started with a consent form (Appendix B), 

24 

 
 
 
 
explaining the purpose of the study, potential benefits and risks, information regarding privacy 

and confidentially, and what participants were expected to do. The consent form explained that 

the purpose was to gather input on how people define and perceive stuttering severity. No 

personal information was requested, with the exception of the email address, which was optional, 

because it could help researchers if they wanted to follow up with questions if needed. 

Demographic data was collected, including age, racial identity, ethnicity, and country of 

birth. For people who stutter, information about prior speech therapy and self-help/support group 

participation was requested. For speech-language pathologists, information about years of 

experience and if stuttering was their area of expertise was asked. This data was used to describe 

the study participants. All participants were asked to answer three open-ended questions about 

stuttering severity (Appendix C). The same questions were asked to both groups so that answers 

could be compared. A definition of stuttering severity was not provided, so that participants 

could provide their own responses in an unbiased manner. In order to gather a variety of 

perspectives, the questionnaire was available in English, Spanish, and Portuguese. Prior to full 

data collection, the questionnaire was tested in the three languages by one person who stutters 

(English speaker), one speech- language pathologist (Spanish speaker), and one person who is 

both a person who stutters and a speech-language pathologist (Portuguese speaker). The goal of 

the pilot testing was to identify and correct possible ambiguities or errors. The results of this 

testing indicated that no revisions or edits were needed. 

A total of 400 participants completed the questionnaires in English, Spanish, or 

Portuguese. Of these, 115 responses were in English, and these are the responses that were 

analyzed in this study. Responses in Spanish and Portuguese will be examined at a later date. 

Within the sample of the English-speaking participants, 47 were people who stutter, 50 were 

25 

 
 
 
speech-language pathologists, and 18 were both people who stutter and speech-language 

pathologists. No follow-up questions were included in the study. Participant demographic 

information of people who stutter can be found in Table 2. 

Table 2. Demographic data – People who stutter 

Demographic data – People who stutter 

Demographic variable 

Age (years)  
Racial identity  

-  American Indian or Alaskan Native 
-  Asian  
-  Black or African American  
-  Native Hawaiian or other Pacific 

Islander 

-  White 
-  Other  
-  Prefer not to say/missing data  

Ethnicity  

-  Not Hispanic or Latino 
-  Hispanic or Latino  
-  Prefer not to say/missing data 

History of stuttering therapy  

-  Yes 
-  No 
-  Prefer not to say/missing data  
History of self-help or support groups  

-  Yes 
-  No 
-  Prefer not to say/missing data  

Country/continent of birth 
-  United States 
-  North America (not the United States) 
-  South America 
-  Europe  
-  Asia  
-  Africa 
-  Oceania  
-  Prefer not to say/missing data  

% or range 

8 – 75 years old  

0% 
10.87% 
0% 
0% 

65.22% 
10.87% 
13.94% 

78.26% 
6.52% 
15.22% 

80.43% 
8.70% 
10.87% 

80.43% 
8.70% 
10.87% 

32.61% 
4.35% 
0% 
34.78% 
10.87% 
2.17% 
0% 
15.22% 

Participant demographic information of speech-language pathologists can be found in 

Table 3. 

26 

 
 
 
 
 
 
 
 
 
 
Table 3. Demographic data – Speech-Language Pathologists 

Demographic data – Speech-Language Pathologists 

Demographic variable 

Age (years)  
Racial identity  

-  American Indian or Alaskan Native 
-  Asian  
-  Black or African American  
-  Native Hawaiian or other Pacific 

Islander 

-  White 
-  Other  
-  Prefer not to say/missing data  

Ethnicity  

-  Not Hispanic or Latino 
-  Hispanic or Latino  
-  Prefer not to say/missing data 

Stuttering as an area of expertise  

-  Yes 
-  No 
-  Prefer not to say/missing data  

Years of practice  

Country/continent of birth 
-  United States 
-  North America (not the United States) 
-  South America 
-  Europe  
-  Asia  
-  Africa 
-  Oceania  
-  Prefer not to say/missing data  

% or range 

23 – 68 years old  

0% 
6.52% 
0% 
0% 

86.96% 
4.35% 
2.17% 

80% 
8% 
10% 

70.59% 
9.80% 
19.61% 
1 - 50 years  

50.98% 
1.96% 
1.96% 
13.73% 
5.88% 
0% 
0% 
21.57% 

Participant demographic information of people who stutter who are also speech-language 

pathologists can be found in Table 4. 

Table 4. Demographic data – Speech-language pathologists who stutter 

Demographic data – Speech-language pathologists who stutter 

Demographic variable 

Age (years)  

% or range 

21– 69 years old  

27 

 
 
 
 
 
 
 
 
 
 
 
Table 4 (cont’d) 

Racial identity  

-  American Indian or Alaskan Native 
-  Asian  
-  Black or African American  
-  Native Hawaiian or other Pacific 

Islander 

-  White 
-  Other  
-  Prefer not to say/missing data  

Ethnicity  

-  Not Hispanic or Latino 
-  Hispanic or Latino  
-  Prefer not to say/missing data 

History of stuttering therapy  

-  Yes 
-  No 
-  Prefer not to say/missing data  
History of self-help or support groups  

-  Yes 
-  No 
-  Prefer not to say/missing data  

Stuttering as an area of expertise 

-  Yes 
-  No  
-  Prefer not to say/missing data 

Years of expertise 
Country/continent of birth 
-  United States 
-  North America (not the United States) 
-  South America 
-  Europe  
-  Asia  
-  Africa 
-  Oceania  
-  Prefer not to say/missing data  

0% 
16% 
0% 
0% 

64% 
0% 
20% 

80% 
0% 
20% 

83.33% 
16.67% 
0% 

83.33% 
16.67% 
0% 

86.96% 
0% 
13.04% 
0.5 – 26 years  

61.11% 
5.56% 
0% 
16.67% 
22.22% 
0% 
0% 
0% 

A thematic analysis was conducted on responses to the three open ended questions in 

Appendix C. A narrative comparison of the thematic analysis to the literature review project on 

existing definitions of stuttering severity was then completed. Thematic analysis is a method to 

identify, analyze, and report patterns (themes) found in the data (Braun & Clarke, 2006). This 

28 

 
 
 
 
 
 
 
 
 
 
 
 
study used an internet-based administration in order to increase the number of participants and to 

get responses from a variety of experiences and backgrounds (Tichenor & Yaruss, 2019). 

The first author, who is a person who stutters, answered the questions first, in order to 

reduce unintentional bias and a possible inclination of researchers to interpret the participant’s 

responses through the lens of their own experience (Creswell, 2013). Answers indicated that 

from her perspective, stuttering severity is the intensity in which a person responds to the sense 

of loss of control while speaking, which is not always visible to others. Some aspects or areas 

that constitute stuttering severity include awareness, reactivity (tension, struggle), regulation, and 

spontaneity. Factors that influence severity include personal reactions to the sense of loss of 

control (cognitive, emotional, behavioral), environmental factors, and variability.  

To analyze the data, the six steps proposed by Creswell (2013) were followed: Step 1: 

organize and prepare data for analysis. Step 2: read and observe all the data and get general ideas 

about what was mentioned by the participants. Step 3: start data coding, which includes 

organizing relevant data according to the objective of the investigation. Step 4: use decoding and 

generate categories, and then use the codes found previously to group them by similarity into 

themes or categories, which will be the main study findings. Step 5: describe the topics and 

narratively describe the results of the analysis depending on the objective of the research and the 

topics found. Step 6: interpret the results, and compare the information found with what is raised 

in the literature. The researcher can mention if the findings confirm what was raised in the 

research or if they differ from them, as well as raise new questions for future research.  

Data were evaluated in terms of “themes,” and, in the descriptions below, quotes from 

each group are included to illustrate these themes. This study used a triangulation approach in 

order to enhance the trustworthiness and validity of the findings. Triangulation is a way to 

29 

 
 
 
explore different perspectives on the same phenomenon (Fusch & Ness, 2015). The participants 

include clinicians and people who stutter, and, as the authors suggested, it is important to keep in 

mind that contradictory results could be obtained. However, it is the responsibility of the 

researchers to interpret the findings in a way in which they can demonstrate the richness of the 

information obtained from the data. Saturation analysis was not conducted because the data 

included a very large sample and participants from different backgrounds, which supports the 

idea that the themes and subthemes reflect a deep understanding of the topic and is credible 

(Fusch & Ness, 2015). 

In conclusion, this study aimed to combine the perspectives of both clinicians and people 

who stutter. Through a qualitative study, and a survey distributed online on different internet 

platforms, researchers explored the concept of stuttering severity. The findings are expected to 

improve the use of this concept, which is widely used in the assessment, treatment, and research 

of this condition.   

30 

 
 
 
 
 
Results 

Three open-ended questions were included in the survey to explore and analyze the 

concept of stuttering severity. The analysis results are presented in two main sections. The first 

section focuses on the analysis of questions 1 and 2, the definition and components of stuttering 

severity; the second section focuses on question 3, the factors that influence stuttering severity. 

This division is based on the similarity of responses to the first two questions, with the purpose 

of enhancing the clarity and organization of the findings.  

Definition and Components of Stuttering Severity  

A compilation of all the themes across all the participants regarding the definitions and 

components of stuttering severity is presented in Table 5. Many themes resonated consistently 

across all the three participants groups; thus, they are addressed first. However, distinct patterns 

depending upon whether the respondent was a person who stutters were also observed. 

Particularly, there were two distinct themes exclusively observed in the responses of individuals 

who stutter, encompassing both those who were speech-language pathologists and those who 

were not. Those particular themes are presented separately.  

Table 5. Definition and components of stuttering severity 

Definition and components of stuttering severity 

People who stutter 

Speech-language 

Speech-language 

pathologists who Stutter 

pathologists 

Internal Struggle and Effort 

Internal Struggle and Effort 

Struggle May Not Be Visible  Struggle May Not Be Visible 

Disfluencies and Visible 

Disfluencies and Visible 

Disfluencies and Visible 

Physical Tension 

Physical Tension 

Physical Tension 

31 

 
 
 
 
 
Table 5 (cont’d) 

Effective Communication 

Effective Communication 

Effective Communication 

Affective, Behavioral, and 

Affective, Behavioral, and 

Affective, Behavioral, and 

Cognitive Responses 

Cognitive Responses 

Cognitive Responses 

Adverse Impact 

Adverse Impact 

Adverse Impact 

Variability 

Variability 

Variability 

People who Stutter, Speech-Language Pathologists who Stutter, and Speech-Language 

Pathologists 

Analysis of questions 1 and 2 revealed five themes exploring the concept of stuttering 

severity: (a) Disfluencies and Visible Physical Tension; (b) Effective Communication; (c) 

Affective, Behavioral, and Cognitive Responses; (d) Adverse Impact; and (e) Variability. Some 

responses did not fit with the other themes, so these were collected into a Miscellaneous 

category. 

Disfluencies and visible physical tension 

Participants defined stuttering severity as the degree of visible disruption in the fluency of 

speech, including factors such as the frequency, duration, and types of stuttering events. 

Stuttering events themselves were defined as observable behaviors such as blocks, prolongations, 

and repetitions. Severity also includes physical concomitant behaviors, body movements, and 

outward tension during moments of stuttering.  

32 

 
 
 
 
 
 
 
 
People who stutter:  

Participant 25 (P25): I have generally defined stuttering severity by the frequency and 

intensity of physical struggle combined with the frequency and intensity of avoidance 

behaviors. 

P37: I would define stuttering severity using a combination of factors, for example, 

stuttering types and durations, physical tension… 

Speech-language pathologists who stutter: 

P100: How frequently someone stutters, duration of stuttering, and physical 

concomitants. 

P102: Primary characteristics = ratio of stuttering vs. fluent speech, how much 

interjections or other non-stuttering-like disfluencies are used, length of stuttering 

moments. Secondary behaviors = distinct lack of eye contact, excessive hand/body 

movements, etc. 

Speech-language Pathologists:  

P55: I define stuttering severity based on frequency, duration, and physical concomitant 

behaviors as outlined by the SSI. 

P56: I define stuttering severity as how pronounced the stutter sounds/looks to a listener.  

P59: I define stuttering severity as the number of repetitions, blocks, and/or 

prolongations in samples of a person’s speech taken over time. 

P85: One meaning is the degree of disruption/distraction of stutter events on speech 

delivery (severity of dysfluency). 

33 

 
 
 
 
 
Effect on communication   

Stuttering severity is related to the freedom the person who stutters feels in expressing 

themselves and their ability to communicate openly. In that regard, a greater severity means that 

it is harder for the person to say what they want to say.  

People who stutter: 

P28: I personally define stuttering severity as how well a person finds him/herself able to 

communicate what s/he wants to say. 

P29: I define it as (…) the amount that stuttering has on their ability to communicate in a 

way they would like to… 

P30: I define stuttering severity as the degree to which it limits a person in expressing 

themselves.  

Speech-language pathologists who stutter: 

P95: The amount of freedom a person feels to speak. So, to which amount can he/she say 

exactly what he wants -and when- to say. 

P107: I define stuttering severity by a combination of how often and how much someone 

stutters (in terms of physical concomitants) as well as life impact (if someone avoids a lot 

or is not saying what they want to say). 

Speech-Language Pathologists:  

P57: I really define severity based on (…) how severely it limits allowing a person to say 

what they want to say. 

P71: I define stuttering severity as the level at which it affects communication. Although 

the main signs of stuttering include repetition, block, or any kind of avoidance, in my 

view it can be measured based on its effects on communication.  

34 

 
 
 
P83: I define stuttering severity as how much the stuttering negatively impacts one's life. 

Is the stuttering preventing this person from communicating in certain settings, or saying 

what they would like to say?  

Affective, Behavioral, and Cognitive Responses 

Stuttering severity also involves the impact on an individual's emotional, cognitive, and 

behavioral dimensions. This includes the degree to which stuttering affects feelings, thoughts, 

attitudes, and confidence, among others. It involves examining how often they feel that way, 

thoughts and reactions related to stuttering, how much of the time they think about the way they 

speak, what do they think, and how intrusive those thoughts are. In that regard, a greater negative 

affective, behavioral, and cognitive responses equals a greater severity. 

People who stutter: 

P22: The emotions you feel when communicating or anticipating speaking. The greater 

the negative emotions you feel about speaking (before and after) are a good barometer of 

stuttering severity. 

P39: Severity: as it influences my life, my thoughts, my willingness to talk, and how I 

behave. 

Speech-language pathologists who stutter: 

P98:  I think some of those different things include (but are not limited to): 

- How good or bad someone feels about the way they speak 

- How often do they feel that way about the way they speak 

- How much of the time they think about the way they speak… 

P99: The amount of negative thoughts or feelings that I experience after moments of 

stuttering. 

35 

 
 
 
Speech-language Pathologists:  

P52: I define stuttering severity to the tune of how much (or how little) the affective, 

behavior, and/or cognitive aspects of stuttering may (or may not be) holding a person 

back from saying exactly what they want to say, when they want to say it. 

P54: I define stuttering severity as a culmination of the affective, behavioral, and 

cognitive components of the condition. Stuttering severity includes the person's thoughts 

and feelings related to stuttering… 

P92: Are they so embarrassed/ anxious/ frustrated about their stuttering that they shut 

down in class/ refuse to speak. 

Adverse Impact  

Stuttering severity involves how much stuttering limits the speaker’s participation in 

different activities, including what are they doing (or not doing) because of previous experiences 

associated with stuttering. This involves evaluating the level of negative influence across various 

life areas, including daily living situations, relationships, and future plans. 

People who stutter: 

P19: I relate stuttering severity to how it affects your daily living. 

P22: I define stuttering severity as the impact of stuttering on one’s everyday life. The 

negative emotions, limitations, and the real-world environment that effects that negatively 

impact their ability to participate in everyday life activities.    

P23: I define stuttering severity as the level of limited personal and social activities with 

other people, which could influence my quality of life as a person who stutters. 

P27: I would define severity as the level of disfluency and level of impairment in daily 

life that the stutter causes. 

36 

 
 
 
Speech-language pathologists who stutter: 

P99: Participation in activities (speaking related mostly) is impacted by their stuttering.  

P100: I define stuttering severity as how much stuttering hinders our lives. 

P102: Participation and activity limitations (i.e., what are they doing or not doing 

because of stuttering). 

P109: The second factor would be how the individual experiences stuttering, that is, how 

much does stuttering affect them in all aspects of life? How limiting is the stuttering to 

their quality of life? Participation in work, hobbies, and socialization? In short, I define 

stuttering as both the severity of overt characteristics (primary and secondary behaviors) 

and the impact it has on an individual's life. 

Speech-language Pathologists:  

P48: I define stuttering severity as the level at which a person’s life is negatively 

impacted. How much does the stigma of stuttering negatively impact the person’s 

participation and satisfaction across the many facets of their life. 

P79: I would define severity according to how it affects the client's ability to function in 

their daily activities, work, school, and interactions with others. 

P88: I define stuttering (stammering) severity as how much stammering impacts the 

person who stammers well-being and participation across different situations. 

P89: The most important indicator of severity is how it affects the person who stutters in 

life. E.g., do they avoid participation in things they would otherwise do due to their 

stutter. 

37 

 
 
 
 
 
Variability  

Stuttering severity varies both within and between individuals. Within an individual, 

stuttering severity varies based on the context in which speech occurs, and the self-perspective of 

the speaker. And, different people experience stuttering severity differently. Notably, every 

component of stuttering severity varies. (Note that additional information regarding factors that 

influence severity and variability are presented in the analysis of the question 3, under the section 

“Factors that influence stuttering severity.”) 

People who stutter: 

P7: Stuttering severity should be defined in different contexts, as different contexts lead to 

different fluency experiences (talking to yourself isn't the same as talking to an audience). 

P32: I would say the severity depends on personal experience. One might call themselves 

a person with a severe stutter, while someone with the same 'stutter frequency' might not 

experience the stutter to be severe. People who are good at avoiding their stutters to be 

heard by their listeners (coverts) could still have a 'severe' stutter, while nothing is 

noticeable to outsiders. 

Speech-language pathologists who stutter: 

P104: This can vary from person to person over physical, emotional, and cognitive. 

Speech-Language Pathologists: 

P79: Variability of any of the components. 

Miscellaneous Responses 

Some participants indicated that they avoid using the term severity because it is 

necessarily or inherently focused on observable characteristics, such as the number of syllables 

stuttered, and thereby missing the internal experience. They also stated that the term severity 

38 

 
 
 
 
assumes that stuttering must be fundamentally negative, limiting it to only negatives or the 

absence of negativity. 

People who stutter: 

P26: I prefer pronounced as it is less judgmental… 

P40: I no longer really think in terms of stuttering severity. It is too complicated to 

explain to somebody what people can mean when they say this. In the past, I interpreted 

stuttering severity as the frequency or percentage in which stuttering moments happened 

in a conversation, as this is what was recorded in speech therapy. But this no longer 

seems like a helpful measure in any way. 

Speech-language pathologists who stutter: 

P107: I choose to avoid using the term 'severity' as I think a general/layperson 

understanding would assume it refers to observable symptoms so I think it can too easily 

be understood in different ways (…) But I think the term severity has become increasingly 

problematic as I've moved towards viewing stuttering as a difference rather than a 

disorder. Severity carries a strong implicit negative (…) I also have an issue with the 

term 'severity' because it doesn't make space for anything positive. It only allows for 

negatives or the absence of negativity (…). There’s a huge assumption built into the term 

stuttering severity that stuttering MUST be bad. There's no shred of possibility of 

anything good in it. 

Speech-Language Pathologists: 

P44: I would not define severity as it relates to stuttering because I disagree with the 

concept and connotations of it being used to rate or count the amount of stuttering as % 

39 

 
 
 
syllables stuttered. I feel there is more value in considering the impact on the person and 

how it affects their well-being and quality of life. 

P60: I don't define severity. I talk about stammering more or less / increase or decrease… 

Other participants declined to define stuttering severity. Instead, they defined the “impact” of 

stuttering.  

P52: Impact on the individual who is stammering: Their physical experience and their 

psychological response. 

P74: The impact of stuttering can be: -  physical, when people report tiredness and 

physical tension leading to being exhausted after talking - emotional, when anxiety, 

stress, and strong emotions have an effect on the person before, during, and after 

conversations - cognitive, when "fight or flight" attitudes lead to thoughts considered as 

having a negative impact on the person's self-confidence – social, when stigma around 

stuttering is high and family or work environment have attitudes impeding the person's 

ability to live the life he/she wants. 

Themes Unique to People Who Stutter 

Analysis of questions 1 and 2 revealed two themes that were exclusively reported by 

people who stutter (including those who are speech-language pathologists and those are who are 

not): (a) Internal Struggle and Effort and (b) Struggle may not be visible.  

Internal Struggle and Effort  

Stuttering severity is the degree of the internal struggle and physical or mental effort 

involved in navigating moments of being stuck, either in attempt to hide the moment of being 

suck, in an attempt to escape from the moment of being stuck, or in an attempt to talk even 

40 

 
 
 
though they feel stuck. In that regard, the more the internal struggle and effort, the more severe 

stuttering is. 

People who stutter: 

P1: Severity for me means how much you struggle with your own stuttering. So not how 

much you hear, but how big is the struggle inside.  

P16: For me, severity is the noticeable attributes of the stutter and the effort taken to 

communicate appropriately. 

P26: How long and intense someone is stuck in their words. 

Speech-language pathologists who stutter: 

P96: Stuttering severity relates to the degree to which the speaker is forcing sound...  

P102: We base our diagnosis on the frequency and intensity of stuttered events (…) By 

intensity I mean, how “stuck” the person feels they are. A more severe stutter requires 

more mental and physical effort to move past, to get unstuck, than a less severe stutter. 

Very mild stuttering may require little effort or attention, while severe stuttering might 

require great amounts of both. 

Struggle may not be visible  

The speaker’s sense of internal struggle is not always visible to others; however, it 

becomes evident when manifested through audible and/or visible behaviors, particularly when 

the person is forcing speech. A more severe stutter requires greater mental and physical efforts to 

navigate moments of being stuck. Covert stutterers, individuals who experience few interruptions 

but frequent avoidance strategies such as word substitutions, may not appear severely affected by 

overt stuttering, but can still be impacted by their condition. This was demonstrated in the 

following quotes: 

41 

 
 
 
People who stutter: 

P26: Individuals who have very few interruptions with little struggle but exhibit a high 

frequency of avoidance (word substitutions, circumlocutions, etc.), so-called covert 

stutterers, may not be considered severe in terms of overt stuttering but may be severely 

impacted. 

P34: People who are good at avoiding their stutters to be heard by their listeners 

(coverts) could still have a ‘severe’ stutter, while nothing is noticeable to outsiders. 

Speech-language pathologists who stutter: 

P102: We base our diagnosis on the frequency and intensity of stuttered events. These 

events might result in disfluencies, but they might not… The more severe stutter requires 

more mental and physical effort to move past, to get unstuck, than a less severe stutter… 

P96: The greater the amount of forcing, the more audible and visual features will 

accompany that moment…  

Summary of Definitions and Components of Stuttering Severity 

According to the participants in this study, stuttering severity encompasses the degree of 

internal struggle and physical or mental effort involved in navigating moments of being stuck, 

either in an attempt to hide the moment of being stuck, in an attempt to escape from the moment 

of being stuck, or in an attempt to talk even though they feel stuck. The speaker’s sense of 

internal struggle is not always visible to others; however, it becomes evident when manifested 

through audible and/or visible behaviors, particularly when the person is forcing speech. A more 

severe stutter requires greater mental and physical effort to work through moments of being 

stuck. 

42 

 
 
 
 
Stuttering severity, when it is visible, includes disruptions in speech fluency and the 

frequency, duration, and types of dysfluencies, including blocks, prolongations, and repetitions, 

along with accompanying physical manifestations and tension. It includes the speaker's 

perceived freedom in communication, in which greater severity denotes higher difficulty in 

expressing oneself openly. Additionally, stuttering severity involves emotional, cognitive and 

behavioral dimensions, and the adverse impact that it has on one’s life. Stuttering severity varies 

across individuals, contexts, and perspectives. 

Factors that influence stuttering severity  

This section provides an analysis of question 3, which centers on participants' perceptions 

regarding the factors that influence stuttering severity. Themes common across the three groups 

of participants are presented first. One theme was apparent only in the responses of participants 

who stutter (including both those who were speech-language pathologists and those who were 

not), so this theme is presented separately. 

People who Stutter, Speech-Language Pathologists who Stutter, and Speech-Language 

Pathologists 

Analysis of the question 3 revealed seven themes regarding the factors that influence 

stuttering severity, across all groups of participants: (a) Psychological Factors; (b) Speech-

Language Factors; (c) Perspectives and Responses of the Listeners; (d) Speech Therapy 

Experiences; (e) Situational Factors; (f) Culture Factors; and (g) Individual Factors. A 

compilation of all the themes across all the participants regarding the factors that influence 

stuttering severity is presented in Table 6. 

43 

 
 
 
 
 
 
 
 
Table 6. Factors that influence stuttering severity 

Factors that influence stuttering severity 

People who stutter 

Speech-language 

Speech-language 

pathologists who stutter 

pathologists  

Force to produce speech  

Force to produce speech 

Psychological Factors 

Psychological Factors 

Psychological Factors 

Speech and Language Factors  Speech and Language Factors 

Speech-Language Factors 

Perspectives and Responses 

Perspectives and Responses 

Perspectives and Responses 

of the Listeners 

of the Listeners 

of the Listeners 

Speech Therapy Experiences 

Speech Therapy Experiences 

Speech Therapy Experiences 

Situational Factors 

Situational Factors 

Situational Factors 

Cultural Factors 

Cultural Factors 

Cultural Factors 

Individual Factors. 

Individual Factors. 

Individual Factors. 

Psychological factors 

Various psychological factors influence stuttering severity. Examples include emotional 

states, such as mood, stress, anxiety, uncertainty, and fear of being perceived as a person who 

stutters; personal attributes, such as personality, confidence, resilience, temperament, coping 

skills, self-advocacy, and self-image; reactions, such as feelings and thoughts about stuttering; 

and other factors such as mental and spiritual well-being.  

People who stutter: 

P2: Mood/confidence in how you go about stuttering. 

P6: Stress, anxiety, feeling unsure of yourself. 

44 

 
 
 
 
 
 
 
P13: The biggest factor for me was fear...Fear of being seen as a person who stutters. 

P16: Personality, thought patterns. 

P25: The stutterer's self-image. 

P37: Dependent on an individual's temperament. 

Speech-language pathologists who stutter: 

P87: Feelings and thoughts (shame, doubt, negative self-talk). 

P94: Anxiety. 

P101: Related to the person's tolerance of hearing themselves stutter. 

P102: The person who stutter's current physical, emotional, mental, and spiritual health. 

P104: Having a firm foundation of self-advocacy, coping, and resilience to navigate 

spaces where stuttering is not understood or acceptable. 

Speech-language pathologists: 

P88: Temperament and personality. 

P92: It can be affected by the emotions that arise in someone during communication. It 

can also be influenced by the ways of coping with stuttering. 

P100: Feeling that there is something wrong with them, anxiety surrounding 

speaking/fear of judgment, etc. 

Speech and language factors 

Several factors related to speech and language influence stuttering severity. Examples 

include using multiple languages, speech tasks, encountering challenging letters or words, 

utterance length, language proficiency, speech rate, so-called “feared” words, perceived speech 

fluency, and more.  

People who stutter: 

45 

 
 
 
 
 
 
 
P3: The number of repetitions at a particular syllable, the state of our mouth, and facial 

expressions when we get a blockage (when we get stuck on a syllable). 

P6: Talking in a second or third language. 

P10: Speech tasks. 

P19: Letter or word.   

Speech-language pathologists who stutter: 

P91: Linguistic, paralinguistic, and social factors. 

P92: Words prone to stutter (…), perceived fluency of speech. 

P100: It can be a lot of factors like rate of speech (…), the language that I speak. 

Speech-language pathologists: 

P69: Linguistic factors are obvious like initial word position, length of the utterance. 

P73: Language - if someone is using language which is in their remit they might have less 

severe stuttering, especially in children. 

P85: What does the overt struggle look like. 

Perspectives and responses of the listeners 

Various perspectives and responses of the listener influence stuttering severity. Examples 

include the reactions of people in the individual's environment such as parents, friends, and 

colleagues, which include the thoughts, beliefs, attitudes, and moods of listeners. Additionally, 

the perceptions of stuttering in childhood by parents or caregivers can impact severity.  

People who stutter: 

P16: Reactions of people around us, mostly parents, but also friends, colleagues, etc. 

P25: Attitude/mood of the listener. 

46 

 
 
 
P32: Parent/caregiver/SLP perception of their stuttering at an early age can influence the 

relationship a child has towards their stuttering. If a child was in a setting that praised 

fluency and presented consequences when stuttering occurred, then that child might 

develop a negative relationship towards their stuttering. This starts to develop their 

“iceberg” that can be carried into adulthood which influences increased stuttering 

severity. 

Speech-language pathologists who stutter: 

P99: Supportive and unsupportive people. 

P104: Children who stutter’ parents’ ability to regulate with child/or provide a safe space 

to stutter/live into the identity of the person who stutters. 

Speech-language pathologists: 

P42: Negative/positive responses from others. 

P46: Reactions of the environment to the way the person who stutters speaks. 

P52: Parental support, reactions of others, and peer acceptance. 

P73: Thoughts and beliefs (and ultimately physical actions or words) held by those in the 

lives of a person who stutters that can positively or negatively impact a person who 

stutters view of themselves. 

Speech therapy experiences 

Speech therapy can influence the severity of stuttering positively or negatively. Some 

respondents emphasized the importance of speech techniques to facilitate smoother stuttering 

and reduce severity, while others were against a focus on fluency, noting potential negative 

effects such as decreased self-confidence or enjoyment in speaking. According to these 

participants, early perceptions of stuttering, particularly in environments that praise fluency and 

47 

 
 
 
 
 
penalize stuttering, can shape a negative relationship with stuttering, potentially increasing its 

severity in the long term. Additionally, delayed intervention may increase the severity of both the 

emotional and physical aspects of stuttering, in comparison to those who received therapy 

earlier. 

People who stutter: 

P32: SLP perception of their stuttering at an early age can influence the relationship a 

child has towards their stuttering. If a child was in a setting that praised fluency and 

presented consequences when stuttering occurred, then that child might develop a 

negative relationship towards their stuttering. This starts to develop their “iceberg” that 

can be carried into adulthood which influences increased stuttering severity. 

Participant 39: I think the later a child receives help and support the more difficult the 

task of combating the emotional and physical responses to stuttering. 

Speech-language pathologists who stutter: 

P104: If in speech therapy, working with an SLP who provides/facilitates holistic care, 

NOT just focused on fluency shaping. 

Speech-language pathologists: 

P41: Their use of strategies to help them stutter more easily. 

P54: Focusing too much on fluency or using various techniques, antiquated speech 

therapy that doesn’t educate the person and improve self-confidence and enjoyment in 

speaking. 

P56: The understanding and deployment of the strategies required to help support 

fluency. 

48 

 
 
 
P74: Experiences in Speech-Language Therapy - fluency therapy may have a negative 

impact if a child perceives stammering negatively or as 'failing to improve' in speech 

therapy. 

Situational factors  

The situation a person is in and the activity they are completing affect the severity of 

stuttering: some situations are more challenging and therefore are associated with higher 

stuttering severity. This relationship differs for each individual. For example, stuttering severity 

increases during high-pressure situations like job interviews or phone conversations, particularly 

when speaking to unfamiliar individuals or in noisy environments. Factors such as background 

noise and unfamiliarity can also contribute to variations in stuttering severity. Additionally, the 

composition of the audience and the speaker's comfort level with the situation play important 

roles, with stuttering severity often escalating in group settings or when interacting with 

challenging individuals.  

People who stutter: 

P11: Situation, e.g., will be worse in job interview rather than speaking to friend. Often 

worse on phone. 

P23: Unfamiliarity. 

P31: Background noise (…), situations where I’m a long way out of my comfort zone.  

Speech-language pathologists who stutter: 

P92: Challenging situations, challenging people. 

P100: Stuttering severity can be impacted by environmental factors such as the person 

you are talking to and the situation you are in. 

49 

 
 
 
P102: Factors may include the environment or situation (work, work conference, 

conversational interactions with time-pressure expectations, family or close friends, 

small vs large social groups), the individual the person is speaking with (closer 

relationships vs. acquaintances, the position of the communication partner such as a 

boss, subordinate, customer service representative, or police officer, etc.) 

Speech-language pathologists: 

P76: Stuttering can be affected by different communicative situations. It may be easier to 

speak one to one with another speaker while in a group situation, stuttering may increase 

(…) Talking on the phone may be more difficult for some people. Unfamiliarity with given 

situations. 

Cultural factors  

Cultural factors and community support influence stuttering severity. These include 

societal attitudes towards stuttering, exposure to diverse stuttering groups, media representation 

impact, and government regulations on support. Stigma, discrimination, and bullying within 

family, social circles, schools, and workplaces also play a role.  

People who stutter: 

P9: Cultural and social attitudes. 

P30: How society views stuttering, exposure to other diverse groups of stuttering, 

government regulations on what's needed to gain support in different countries. 

P34: Would be influenced by stigma, faced with family, and other parts of their social 

life, and school, and work. 

Speech-language pathologists who stutter: 

P98: Environment (family, school, daycare, work, hobbies), society. 

50 

 
 
 
P104: If the child/child's family or person is connected to any stuttering support 

groups/community, representation in the world, media, books, etc. 

Speech-language pathologists 

P51: Community/support factor: a person's stuttering severity may be affected by their 

level and type of support. This could be from community or family support. Culture- A 

person's stuttering severity is very likely to be impacted by their culture, specifically how 

their society views disability. Communities embracing the medical model of disability 

may empower people who stutter to experience the condition in a positive light. 

Contrarily, people living in societies that abide by the medical model of disability may 

experience more severe stuttering due to participation restrictions. 

P74: Culture and societal views of stammering (…), bullying, discrimination and stigma 

about stammering. 

Individual factors  

Individual factors influence the severity of stuttering, from external circumstances to 

internal states. Financial circumstances, daily stress, mental and physical health, and tiredness all 

contribute to the severity of stuttering experienced. Additionally, life problems, co-occurring 

conditions, medication, gender dynamics, and potential genetic and neurological components 

also influence stuttering severity. In that regard, stuttering severity appears to fluctuate day to 

day, hour to hour, minute to minute, or based on the situation, reflecting the variability of its 

manifestation.  

People who stutter: 

P16: Financial circumstances. 

P17: Tiredness, depression, sleep deprivation, and life problems. 

51 

 
 
 
P18: Your health at that moment. 

P26: Daily stress, overall mental health, physical health (feeling good in your body, 

makes you feel more confident which could affect the stuttering experience). 

P31: The balance of men to women I’m talking to. The more men, the more I stutter. Not 

sure why. 

P34: It also would matter if they had other disabilities or disorders. For example, the 

negative impact of stuttering may increase for someone with ADHD who struggles with 

rejection sensitivity dysmorphia.   

Speech-language pathologists who stutter: 

P92: Unpleasant memories related to past speaking experiences.   

P103: I imagine there is a genetic and neurological component. 

Speech-language pathologists: 

P58: Physical health (healthy/sick, tired/alert), medication. 

P63: Changing - job, places to live. 

P80: Stuttering severity seems like it could change day to day, hour to hour, minute to 

minute, or based on the situation. I'd say it could depend on external factors such as 

communication partners, environment, stress, feelings, anxiety, mood, physical needs 

such as being tired/hungry, etc. 

Theme Unique to People Who Stutter  

Analysis of question 3 revealed that one theme was exclusively reported by people who 

stutter, including both those who are speech-language pathologists and those are who were not: 

Force to produce speech. 

Force to produce speech 

52 

 
 
 
 
Participants who stutter highlighted that one factor that influences stuttering severity is 

the degree of force applied to produce speech during moments of feeling stuck, along with the 

motivation that drives that force. Additionally, the internal reactions to stuttering were noted to 

amplify their intensity.  

People who stutter: 

P4: The ability to get out of the blockage and continue speaking. 

P12: The difficulty in controlling it by persons who stutter. 

P21: The more I want to be fluent, the more I stutter. 

Speech-language pathologists who stutter: 

P101: How much the person is forcing sound out at that moment is the key factor related 

to severity. Forcing sound out relates to how much the speaker wants to be done with that 

speaking situation (e.g., related to perceptions of what the listener thinks; related to the 

person's tolerance of hearing themselves stutter). 

P103: Also, some people may react to their stuttering more than others, increasing 

intensity (…). Also, it seems the more one reacts to stuttering the more frequently they 

stutter too. 

Summary of Factors that Affect Stuttering Severity 

Various factors influence the severity of stuttering. This includes the degree of force to 

produce speech, as well as the motivation that drives that force. Psychological factors, such as 

emotional states, personal attributes, reactions, and mental and spiritual well-being, could also 

influence stuttering severity. Apart from that, speech-language factors, such as speech rate, and 

multilingualism; situational factors; like the situation in which the person is in; cultural factors, 

including stigma and discrimination; and individual factors, such as financial circumstances and 

53 

 
 
 
 
daily stress, also contribute to the decrease or increase of stuttering. Additionally, the 

perspectives and responses of the listeners influence stuttering severity, which includes their 

thoughts, beliefs, and attitudes. Finally, participants mentioned that speech therapy experiences 

can either influence severity positively or negatively, according to the perspectives on fluency 

strategies.  

54 

 
 
 
 
 
Discussion 

This section includes an examination and analysis of the findings, as well as an important 

consideration and key aspects of the participants. Additionally, it mentions the limitations of the 

study and future directions.  

Analysis of results  

This study addressed the challenges in defining stuttering severity. The first part of the 

study involved a comprehensive review of over 500 sources in English, Spanish, and Portuguese 

to determine how various authorities in the field have defined stuttering severity. Analyses 

revealed 21 formal definitions of stuttering severity. For instance, Kuniszyk-Jozkowiak (1995, p. 

14) mentions “stuttering severity defined as the number of errors characteristic of stuttering, such 

as: repetitions, insertions, blockades, etc. per 100 syllables,” Klassen (2002, p. 98) explained 

that, “severity is the seriousness of the stuttering, including its length, and behaviors such as 

avoiding eye contact, grimaces, etc.” Yairi and Seery (2021, p. 194) stated that stuttering severity 

is, “the level of disruption in the delivery of continuous speech.”  

Another important finding of the literature review is that some of the well-known 

assessments of severity, such as the Iowa Scale of Severity of Stuttering, the TOCS, and the SSI-

4 did not define stuttering severity. They provided information on how it should be measured but 

did not a definition of what exactly it is. This highlighted the need for a definition of stuttering 

severity to ensure consistency and accuracy in clinical and research practices.  

While the 21 definitions provide us valuable insights regarding how severity might be 

conceptualized, two main issues arise. First, a consideration of all of these definitions reveals a 

lack of consistency or consensus on how severity should be defined. For some authors, severity 

is the measure of frequency and duration, while for others, is the amount of overt stuttering 

55 

 
 
 
 
moments a person exhibits, including speech and body movements, and others define stuttering 

severity based on different factors. The second problem is that nearly all of the definitions are 

focused on the observable characteristics of stuttering that a listener might perceive, such as the 

disfluencies and physical characteristics of moments of stuttering. In contrast, when people 

stutter, they have reported to have “a feeling” inside them (Emerick & Hamre, 1972), described 

by Perkins (1990) as a sense of “loss of control” while speaking (see also Tichenor and Yaruss, 

2019). In that regard, stuttering severity as commonly defined may not capture the internal 

essence of stuttering, that sensation that can only be judged by the person who stutters (Alm, 

1997). 

To further explore the ways in which stuttering is or might be defined, the study gathered 

the perspectives of people who stutter and speech-language pathologists, as well as those who 

are both. Participants were asked to define stuttering severity and explain the factors that 

influence it. People who stutter and speech-language pathologists defined the severity of 

stuttering as the degree of disruptions in speech fluency, including factors like frequency, 

duration, and types of stuttering events. These definitions involve visible physical behaviors and 

body movements, and affective, behavioral, and cognitive dimensions. Participants also 

highlighted that stuttering severity can reflect the extent in which the person limits their 

communication, the adverse impact stuttering has in their lives, and the variability that severity 

has.  

The first common theme, stuttering severity defined as disfluencies and visible physical 

tension, is similar to findings in existing literature. Zebrowski and Kelly (2002, p. 16) stated that 

“severity of stuttering is a global judgment based on listener’s perceptions of the frequency, type, 

and duration of disfluent speech, as well as the presence or absence of associated behaviors.” 

56 

 
 
 
Similarly, Pertijs et al. (2014, p. 164) mentioned that “stuttering severity is a measure based on 

the objective measurement of stuttering behavior, such as stuttering frequency, duration of stutter 

moments, the type of dysfluencies and secondary behaviors.” This demonstrates that the field 

shares a common agreement on this first aspect regarding how stuttering is defined.  

As previously mentioned, the concept of stuttering severity includes more aspects in 

addition to just the number or nature of speech disfluencies. However, the 21 definitions 

identified in the first part of this study are focused primarily on those observable disfluencies and 

physical tension that might be visible to a listener. In that regard, there is a contradiction between 

the current literature and the findings of this study. According to the literature, stuttering severity 

is related to speech disfluencies, but for people who stutter and speech-language pathologists in 

this study, severity includes broader aspects. One possible explanation for this discrepancy is that 

the definitions found in the literature reflect perspectives that historically have been focused on 

speech, while contemporary understandings of severity have broadened the perspectives to a 

more holistic approach, adding factors such as the adverse impact and cognitive and emotional 

responses, among others. Future research should study these viewpoints further and explore the 

broader, multifaceted nature of stuttering severity. 

People who stutter added another theme to these descriptions: the degree of internal 

struggle and physical and mental effort required to talk. They indicated that this struggle may 

sometimes be visible to others and sometimes kept internalized. Interestingly, while speech 

speech-language pathologists who do not stutter provided important insights about severity that 

largely matched the perceptions of people who stutter, they did not identify the internal 

experience that people who stutter reported. In other words, while speech-language pathologists 

did identify observable aspects of stuttering severity, such as the disruptions in the speech, they 

57 

 
 
 
did not fully recognize the significance of the internal struggle and effort required to talk that 

was described by those who stutter. 

This is relevant because the comprehensive review of definitions of severity conducted in 

the first part of this project revealed that severity is defined and evaluated only in terms of 

observable behaviors. Current approaches are therefore failing to fully capture the experience of 

stuttering severity reported by individuals who stutter. Clinicians and researchers could benefit 

from listening to the voices of people who stutter who can share first-hand experiences with 

stuttering and factors that maybe previous research has not investigated. 

Moreover, in the analysis of factors that influence stuttering severity (Question 3), people 

who stutter and speech-language pathologists highlighted a range of consistent factors. These 

included psychological factors, speech-language factors, situational factors, cultural factors, 

individual factors, speech therapy experiences, and perspectives and responses of the listeners. 

Again, however, the participants who stuttered added another theme. They explained that 

stuttering severity is influenced by the degree of force to produce speech while feeling stuck, and 

the motivation that drives that force. As with the two previous questions, speech-language 

pathologists did not identify these internal aspects of stuttering severity, despite the majority of 

them being professionals with stuttering as their area of expertise. This again highlights the fact 

that there is a gap between the clinical and research understanding and the experiences of 

individuals who stutter, which demonstrates the need for research focused on stuttering from the 

perspectives of those who live with it.  

Another important finding from these analyses is the number of factors that influence 

stuttering severity. Analysis of the themes demonstrated that severity can be influenced by the 

force required to produce speech, the motivation that drives that force, psychological factors, 

58 

 
 
 
situational factors, cultural factors, individual factors, speech therapy experiences, and 

perspectives and responses of the listeners. In contrast, the most common assessments designed 

to measure the severity of stuttering, such as the Iowa Scale of Severity of Stuttering, the TOCS, 

and the SSI-4, typically provid a level of severity based on 3 or 4 speech tasks of a few minutes 

each. These may not adequately represent the complexity of stuttering severity due to the 

numerous factors that influence it and cause it to fluctuate rapidly. Indeed, one of the key themes 

identified from this study is the variability of stuttering severity, yet current measures of 

stuttering do not fully account for this variability. Consequently, relying on a small number of 

speech tasks in restricted settings may result in an incomplete understanding of stuttering 

severity for an individual speaker. Future research should look into ways to develop an 

assessment that accounts for the diverse factors that influence stuttering severity, according to 

how impactful are each factor for each person who stutters.  

An important consideration about these participants 

It is critical to note that participants who are both people who stutter and speech-language 

pathologists demonstrated a deep level of insight and sophistication in their responses. This 

could be attributed to their professional training and expertise, as well as their personal 

experiences with stuttering, which allowed them to perceive different aspects of this complicated 

concept of severity. This facilitated having more profound answers that contributed and enriched 

these research findings. At the same time, this introduces a potential confound in the data, as 

these respondents might have had insights that are not common within the general population of 

people who stutter. 

Moreover, the biggest proportion of individuals who stutter had previously received 

stuttering therapy and/or participated in support groups. This is relevant because their responses 

59 

 
 
 
may have been influenced by their previous interventions. Such influences could have shaped 

their perspectives about how severity should be viewed, in comparison who those who have not 

accessed any therapy or support group. An example of this it is shown in the following quote:  

P22: I define stuttering severity as the impact of stuttering on one’s everyday life. The 

negative emotions, limitations, and the real-world environment that effects that negatively 

impact their ability to participate in everyday life activities.    

Additionally, a substantial number of participants were speech-language therapists who 

specialize in stuttering. Again, their experience and expertise in the field also introduce potential 

biases and limit the generalization of the results to bigger populations. For instance, some of the 

answers to the questions include very sophisticated analyses, reflecting the high level of 

understanding and specialization about stuttering, as it is showed in the next quote: 

P51: Community/support factor: a person's stuttering severity may be affected by their 

level and type of support. This could be from community or family support. Culture- A 

person's stuttering severity is very likely to be impacted by their culture, specifically how 

their society views disability. Communities embracing the medical model of disability 

may empower people who stutter to experience the condition in a positive light. 

Contrarily, people living in societies who abide by the medical model of disability may 

experience more severe stuttering due to participation restrictions. 

Future studies should include groups of people who stutter and professionals who have 

less involvement in the stuttering community, to have a more generalizable understanding of 

how people presently define stuttering severity and how might be defined in the future.  

60 

 
 
 
Limitations 

While this research offers valuable insights into the severity of stuttering, it is crucial to 

recognize and address its limitations. One of these is that it was conducted through an online 

survey, which may have limited participants in fully expressing their insights. Many participants 

did enter a considerable amount of text into the response fields, but a face-to-face interview 

could still have provided more detailed and deeper answers. Another limitation of the study is 

that, as with most qualitative research, there is a risk of bias on the researcher due to the 

knowledge and experiences (Nowell et al., 2017), such as being a person who stutters. Even 

though this was addressed by answering the questions before the participants and asking neutral 

questions, analytical bias is always a risk that should be considered.  

Future directions  

The results of this study offer valuable insights and important opportunities for future 

research. For instance, the 21 definitions of stuttering severity identified could receive a more 

comprehensive examination, which could include classifying these definitions into groups to 

gather more clarity on the diverse conceptualizations on the topic.  

Moreover, as noted in the method, data were not only collected from English-speaking 

participants. Approximately 300 responses were also collected from people who speak Spanish 

or Portuguese. These data will be analyzed in the future, and this will provide broader 

perspectives and a bigger understanding of the concept of stuttering severity. Such analyses will 

allow the researchers to conduct cultural comparisons across the different populations.  

In addition, future studies can address the specific themes that participants identified in 

this study. For instance, future studies could gather deeper insights into what the internal struggle 

and effort that people who stutter feel means and it is influence on stuttering severity, since there 

61 

 
 
 
 
are few studies on the topic. Apart from that, this study was conducted on adults who stutter and 

professionals, but future studies should consider the perspectives of younger people who stutter 

to know it their experiences and make comparisons over time. And, people who do not have 

advanced knowledge about stuttering should also be involved, to determine whether the unique 

expertise of this participant group affected the findings.  

62 

 
 
 
 
 
Final Conclusions 

The purpose of this study was to increase understanding of the concept of stuttering 

severity as perceived by people who stutter and by speech-language pathologists. Results 

demonstrate that for all participants stuttering severity involves broader aspects than speech 

disfluencies, and that numerous factors influence stuttering severity. Although speech-language 

pathologists who do not stutter provided valuable insights that aligned the perspectives of 

individuals who stutter, they did not recognize the internal experiences reported by people who 

stutter. This highlights the fact that there is a gap between the clinical and research understanding 

and the experiences of individuals who stutter, which demonstrates the need for research focused 

on stuttering from the perspectives of those who live with it.  

63 

 
 
 
 
 
 
REFERENCES 

Abdul Waheed, S., Khader, P. S. A., Khan, A. A., & Sathick, J. (2022). Feature extraction from 

behavioral styles of children for prediction of severity of stuttering using historical 
stuttering data. International Journal of Speech Technology, 25(4), 803–815. 
https://doi.org/10.1007/s10772-021-09868-2 

Adriaensens, S., Beyers, W., & Struyf, E. (2015). Impact of stuttering severity on adolescents’ 
domain-specific and general self-esteem through cognitive and emotional mediating 
processes. Journal of Communication Disorders, 58, 43–57. 
https://doi.org/10.1016/j.jcomdis.2015.10.003 

Alm, P. (1997). Assessment of Stuttering Severity. University of Alberta, 

Canada.https://doi.org/10.13140/RG.2.2.17626.90564 

Andrade, C. (2010). Perfil familial da fluência da fala: estudo linguístico, acústico e 
eletromiográfico. Pró-fono Revista De Atualização Científica, 22(3), 169–174. 
https://doi.org/10.1590/S0104-56872010000300003 

Andrews, G., & Ingham, R. J. (1971). Stuttering: Considerations in the evaluation of 
treatment. British Journal of Disorders of Communication, 6(2), 129-138. 

Aron, M. L. (1967). The Relationships Between Measurements Of Stuttering Behaviour. 

Journal of the South African Logopedic Society, 14(1), 15-34 

Berrospi, M., Sánches, C., & Cardozo, K. (2018). Indicencia de la Disfluencia en la Calidad de 
Vida en Adultos que asisten al Centro Peruano de Audición, Lenguaje y Aprendizaje 
(CPAL). Pontificia Universidad Catolica del Peru.  

Blomgren, M., Roy, N., Callister, T., & Merrill, R. M. (2005). Intensive stuttering modification 

therapy. Journal of Speech Language and Hearing Research, 48(3), 509. 
doi:10.1044/1092-4388(2005/035).  

Boberg, E., & Kully, D. (1994). Long-term results of an intensive treatment program for adults 
and adolescents who stutter. Journal of Speech and Hearing Research, 37(5), 1050–1059. 
https://doi.org/10.1044/jshr.3705.1050 

Boyle, M. P. (2015). Relationships between psychosocial factors and quality of life for adults 

who stutter. American Journal of Speech-Language Pathology, 24(1), 1–12. 
https://doi.org/10.1044/2014_AJSLP-14-0089 

Braun, V., & Clarke, V. (2006). Using thematic analysis in psychology. Qualitative Research in 

Psychology, 3(2), 77–101. https://doi.org/10.1191/1478088706qp063oa 

64 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Buzzeti, P., Fiorin, M., Martinelli, N., Cardoso, A., & Oliveira, C. (2016). Comparação da 

leitura de escolares com gagueira em duas condições de escuta: habitual e atrasada. Revista 
CEFAC, 18(1), 67–73. https://doi.org/10.1590/1982-0216201618114015 

Carey, B., O’Brian, S., Onslow, M., Block, S., Jones, M., & Packman, A. (2010). Randomized 

controlled non-inferiority trial of a telehealth treatment for chronic stuttering: The 
Camperdown Program. International Journal of Language and Communication Disorders, 
45(1), 108–120. https://doi.org/10.3109/13682820902763944 

Carey, B., O’Brian, S., Onslow, M., Packman, A., & Menzies, R. (2012). Webcam delivery of 
the camperdown program for adolescents who stutter: A phase I trial. Language, Speech, 
and Hearing Services in Schools, 43(3), 370–380. https://doi.org/10.1044/0161-
1461(2011/11-0010) 

Carrasco, E., Schiefer, A., & Azevedo, M. (2015). O efeito do feedback auditivo atrasado na 

gagueira. Audiology - Communication Research, 20(2), 116–122. 
https://doi.org/10.1590/S2317-64312015000200001397 

Cocomazzo, N., Block, S., Carey, B., O’Brian, S., Onslow, M., Packman, A., & Iverach, L. 

(2012). Camperdown Program for adults who stutter: A student training clinic Phase i trial. 
International Journal of Language and Communication Disorders, 47(4), 365–372. 
https://doi.org/10.1111/j.1460-6984.2012.00150.x 

Constantino, C. D., Manning, W. H., & Nordstrom, S. N. (2017). Rethinking covert stuttering. 
Journal of Fluency Disorders, 53, 26–40. https://doi.org/10.1016/j.jfludis.2017.06.001 

Conture, E. (1990). Childhood Stuttering: What is it and who does it? In Cooper Editor (Eds.), 

Research Needs in Stuttering: Roadblocks and Future Directions (pp.02-15) Reports, A 
Publication of the American Speech-Language-Hearing Association.  

Cordes, A. K., & Ingham, R. J. (1994). The Reliability of Observational Data. Journal of 

Speech, Language, and Hearing Research, 37(2), 279–294. 
https://doi.org/10.1044/jshr.3702.279 

Correa, L. (2010). A prosódia na expressão de atitudes na fala de indivíduos com e sem 

gagueira. Universidade Federal de Minas Gerais. 

Costa, J., Ichitani, T., Juste, F., Cunha, M., & Andrade, C. (2019). Ensaio Clínico de 

Tratamento da Gagueira: estudo piloto com variável monitorada, participação do cão na 
sessão de terapia. Codas, 31(5). https://doi.org/10.1590/2317-1782/20192018274 

Creswell, J. (2013). Research design: qualitative, quantitative, and mixed methods approaches 

(4th ed.). California: SAGE Publications.  

65 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
De Sonneville-Koedoot, C., Bouwmans, C., Franken, M. C., & Stolk, E. (2015). Economic 

evaluation of stuttering treatment in preschool children: The RESTART-study. Journal of 
Communication Disorders, 58, 106–118. https://doi.org/10.1016/j.jcomdis.2015.10.006 

De Sonneville-Koedoot, C., Adams, S. A., Stolk, E. A., & Franken, M. C. (2015). Perspectives 
of clinicians involved in the RESTART-study: Outcomes of a focus group. American 
Journal of Speech-Language Pathology, 24(4), 708–716. 
https://doi.org/10.1044/2015_AJSLP-14-0215 

De Sonneville-Koedoot, C., Stolk, E., Rietveld, T., & Franken, M. C. (2015). Direct versus 
indirect treatment for preschool children who stutter: The RESTART randomized trial. 
PLoS ONE, 10(7). https://doi.org/10.1371/journal.pone.0133758 

Douglass, J. E., Constantino, C., Alvarado, J., Verrastro, K., & Smith, K. (2019). Qualitative 

investigation of the speech-language therapy experiences of individuals who covertly 
stutter. Journal of Fluency Disorders, 61. https://doi.org/10.1016/j.jfludis.2019.105713 

Eve, C. L., Onslow, M., Andrews, C., & Adams, R. (1995). Clinical Measurement of Early 
Stuttering Severity: The Reliability of a 10-point Scale. Australian Journal of Human 
Communication Disorders, 23(2), 26–39. https://doi.org/10.3109/asl2.1995.23.issue-2.03 

Emerick, L. & Hamre, C. (1972). An Analysis of Stuttering. Interstate Printers & Publishers 

Fiorin, M., Ugarte, C., Capellini, S., & Oliveira, C. (2015). Fluência da leitura e da fala 

espontânea de escolares: estudo comparativo entre gagos e não gagos. Revista CEFAC, 
17(1), 151–158. https://doi.org/10.1590/1982-021620152014 

Franken, M.C. & Laroes, E. (2021). RESTART-DCM Method. Revised edition 2021. 

https://www.restartdcm.nl  

Fraser, M. (2010). Self-therapy for the stutterer. Stuttering Foundation.  

Fusch, P. I., & Ness, L. R. (2015). Are we there yet? Data saturation in qualitative research. 
Qualitative Report, 20(9), 1408–1416. https://doi.org/10.46743/2160-3715/2015.2281 

Gillam, R. Logan, K. Pearson, N. (2009). TOCS: Test of Childhood Stuttering. Pro-ed.  

Giraud, A. L., Neumann, K., Bachoud-Levi, A. C., von Gudenberg, A. W., Euler, H. A., 

Lanfermann, H., & Preibisch, C. (2008). Severity of dysfluency correlates with basal 
ganglia activity in persistent developmental stuttering. Brain and Language, 104(2), 190–
199. https://doi.org/10.1016/j.bandl.2007.04.005 

Guitar, B. (2019). Stuttering: An integrated approach to its nature and treatment (5th ed.). 

Wolters Kluwer.  

66 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Guntupalli, V. K., Kalinowski, J., & Saltuklaroglu, T. (2006). The need for self-report data in 

the assessment of stuttering therapy efficacy: Repetitions and prolongations of speech. The 
stuttering syndrome. International Journal of Language and Communication Disorders, 
41(1), 1–18. https://doi.org/10.1080/13682820500126627 

Hall, D. E., Lynn, J. M., Altieri, J., & Hospital, E. S. (1987). Inter-intrajudge reliability of the 
stuttering severity instrument vicki difiore seger. Journal of Fluency Disorders,12. 

Hearne, A., Packman, A., Onslow, M., & O’brian, S. (2008). Developing Treatment for 

Adolescents Who Stutter: A Phase I Trial of the Camperdown Program. 
http://www3.fhs.usyd.edu.au/asrcwww/Downloads/index.htm 

Hulit, L. (2004). Straight Talk on Stuttering( 2nd ed). Charles C Thomas Publisher, Ltd.  

Jakubovicz, R. (1997). Gagueira: Diagnóstico e Tratamento. Editora Revinter.  

Johnson, W. Darley, F. & Spriestersbach, D. (1963). Diagnostic Methods in Speech Pathology. 

Harpey & Row Publishers.   

Juste, F., Ritto, A., Silva, K. & Andrade, C. (2016). Diadococinesia sequencial em crianças 

fluentes e com gagueira desenvolvimental persistente: análise da velocidade e tipo do erro 
da consoante alvo. Audiology - Communication Research, 21. 
https://doi.org/10.1590/2317-6431-2015-1646 

Kell, C. A., Neumann, K., Von Kriegstein, K., Posenenske, C., Von Gudenberg, A. W., Euler, 
H., & Giraud, A. L. (2009). How the brain repairs stuttering. Brain, 132(10), 2747–2760. 
https://doi.org/10.1093/brain/awp185 

Kelman, E. & Nicholas, A. (2020). Palin Parent-Child Interaction Therapy for Early Childhood 

Stammering. Routledge.  

Klassen, T. R. (2002). Social distance and the negative stereotype of people who stutter la 

distance sociale et les prt!juges envers les personnes begues. Canadian Journal of Speech-
Language Pathology and Audiology. 26(2), 90-99. 

Kuniszyk-Jozkowiak, W. (1995). The statistical analysis of speech envelopes in stutterers and 
non-stutterers. Journal of Fluency Disorders, 20(1), 11-23.  https://doi.org/10.1016/0094-
730X(94)00006-F 

Lewis, D., & Sherman, D. (1951). Measuring the severity of stuttering. The Journal of Speech 

Disorders, 16(4), 320–326. https://doi.org/10.1044/jshd.1604.320 

Manning, W. & DiLollo, A. (2017). Clinical Decision Making in Fluency Disorders. Plural 

Publishing 

67 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Martin, R. R., Haroldson, S. K., & Triden, K. A. (1984). Stuttering and speech naturalness. 

Journal of Speech and Hearing Disorders, 49(1), 53–58. 
https://doi.org/10.1044/jshd.4901.53 

Millard, S. K., & Davis, S. (2016). The Palin parent rating scales: Parents’ perspectives of 

childhood stuttering and its impact. Journal of Speech, Language, and Hearing Research, 
59(5), 950–963. https://doi.org/10.1044/2016_JSLHR-S-14-0137 

Millard, S. K., Edwards, S., & Cook, F. M. (2009). Parent-child interaction therapy: Adding to 
the evidence. International Journal of Speech-Language Pathology, 11(1), 61–76. 
https://doi.org/10.1080/17549500802603895 

Millard, S. K., Zebrowski, P., & Kelman, E. (2018). Palin parent–child interaction therapy: The 
bigger picture. American Journal of Speech-Language Pathology, 27(3), 1211–1223. 
https://doi.org/10.1044/2018_AJSLP-ODC11-17-0199 

Moïse-Richard, A., Ménard, L., Bouchard, S., & Leclercq, A. L. (2021). Real and virtual 

classrooms can trigger the same levels of stuttering severity ratings and anxiety in school-
age children and adolescents who stutter. Journal of Fluency Disorders, 68. 
https://doi.org/10.1016/j.jfludis.2021.105830 

Naylor, R. V. (1953). A comparative study of methods of estimating the severity of stuttering. 

The Journal of Speech and Hearing Disorders, 18(1), 30–37. 
https://doi.org/10.1044/jshd.1801.30 

Neumann, K., Euler, H. A., Kob, M., Wolff von Gudenberg, A., Giraud, A. L., Weissgerber, T., 
& Kell, C. A. (2018). Assisted and unassisted recession of functional anomalies associated 
with dysprosody in adults who stutter. Journal of Fluency Disorders, 55, 120–134. 
https://doi.org/10.1016/j.jfludis.2017.09.003 

Neumann, K., Euler, H. A., Von Gudenberg, A. W., Giraud, A. L., Lanfermann, H., Gall, V., & 
Preibisch, C. (2003). The nature and treatment of stuttering as revealed by fMRI: A within- 
and between-group comparison. Journal of Fluency Disorders, 28(4), 381–410. 
https://doi.org/10.1016/j.jfludis.2003.07.003 

Neumann, K., Preibisch, C., Euler, H. A., Gudenberg, A. W. Von, Lanfermann, H., Gall, V., & 
Giraud, A. L. (2005). Cortical plasticity associated with stuttering therapy. Journal of 
Fluency Disorders, 30(1), 23–39. https://doi.org/10.1016/j.jfludis.2004.12.002 

Nogueira, P., Oliveira, C., Giacheti, C., & Moretti-Ferreira, D. (2015). Gagueira 

desenvolvimental persistente familial: disfluências e prevalência . Revista CEFAC, 17(5), 
1441–1448. https://doi.org/10.1590/1982-0216201517510214 

Nowell, L. S., Norris, J. M., White, D. E., & Moules, N. J. (2017). Thematic analysis: striving 
to meet the trustworthiness criteria. International Journal of Qualitative Methods, 16(1). 
https://doi.org/10.1177/1609406917733847 

68 

 
 
 
 
 
 
 
 
 
 
 
 
 
O’Brian, S., Carey, C., Lowe, R., Onslow, M., Packman, A., Cream, A. (2018). The 

Camperdown Program Stuttering Treatment Guide. 
https://www.uts.edu.au/sites/default/files/2018-
10/Camperdown%20Program%20Treatment%20Guide%20June%202018.pdf 

O’Brian, S., Hayhow, R., Jones, M., Packman, A., Iverach, L., Onslow, M., & Menzies, R. 
(2023). Lidcombe Program translation to community clinics in Australia and England. 
International Journal of Language and Communication Disorders, 58(2), 295–309. 
https://doi.org/10.1111/1460-6984.12785 

O’Brian, S., Iverach, L., Jones, M., Onslow, M., Packman, A., & Menzies, R. (2013). 

Effectiveness of the Lidcombe Program for early stuttering in Australian community 
clinics. International Journal of Speech-Language Pathology, 15(6), 593–603. 
https://doi.org/10.3109/17549507.2013.783112 

O’Brian, S., Jones, M., Packman, A., Menzies, R., & Onslow, M. (2011). Stuttering severity 

and educational attainment. Journal of Fluency Disorders, 36(2), 86–92. 
https://doi.org/10.1016/j.jfludis.2011.02.006 

O’Brian, S., Onslow, M., Cream, A., & Packman, A. (2003). The Camperdown Program. 

Journal of Speech, Language, and Hearing Research, 46(4), 933–946. 
https://doi.org/10.1044/1092-4388(2003/073) 

O’Brian, S., Packman, A., & Onslow, M. (2004). Self-rating of stuttering severity as a clinical 

tool. American Journal of Speech-Language Pathology, 13(3), 219–226. 
https://doi.org/10.1044/1058-0360(2004/023) 

O’Brian, S., Packman, A., & Onslow, M. (2008). Telehealth delivery of the Camperdown 

program for adults who stutter: a phase trial. Journal of Speech, Language, and Hearing 
Research, 51(1), 184–195. https://doi.org/10.1044/1092-4388(2008/014) 

Oliveira, C. & Pereira, L.(2014). Gagueira desenvolvimental persistente: avaliação da fluência 

pré e pós-programa terapêutico. Revista CEFAC, 16(1), 120–130. 
https://doi.org/10.1590/S1516-18462013005000046 

Onslow, M., & Lowe, R. (2019). After the RESTART trial: six guidelines for clinical trials of 
early stuttering intervention. International Journal of Language and Communication 
Disorders, 54(4), 517–528. https://doi.org/10.1111/1460-6984.12463 

Onslow, M., Webber, M., Harrison, E., Arnott, S., Bridgman, K., Carey, B., Sheedy, S., 

O’brian, S., Macmillan, V., Lloyd, W., & Hearne, A. (2023). The Lidcombe Program 
Treatment Guide. https://www.uts.edu.au/asrc/resources/lidcombe- 

Perkins, W. H. (1990). What is stuttering? Journal of Speech and Hearing Disorders, 55(3), 

370–382. https://doi.org/10.1044/jshd.5503.370 

69 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
Pertijs, M. A. J., Oonk, L. C., Beer, de J. J. A., Bunschoten, E. M., Bast, E. J. E. G., Ormondt, 
van J., Rosenbrand, C., Bezemer, M., Wijngaarden, van L. J., Kalter, E. J., & Veenendaal, 
van H. (2014). Clinical Guideline “Stuttering in Children, Adolescents and Adults,” 
Nederlandse Vereniging voor Logopedie en Foniatrie. 

Picoloto, L., Cardoso, A., Cerqueira, A., & Oliveira, C. (2017). Efeito da retroalimentação 
auditiva atrasada na gagueira com e sem alteração do processamento auditivo central. 
Codas, 29(6), e20170038. https://doi.org/10.1590/2317-1782/201720170038 

Pirinen, V., Loukusa, S., Dindar, K., Mäkinen, L., Hurtig, T., Jussila, K., Mattila, M. L., & 
Eggers, K. (2023). A comprehensive analysis of speech disfluencies in autistic young 
adults and control young adults: group differences in typical, stuttering-like, and atypical 
disfluencies. Journal of Speech, Language, and Hearing Research, 66(3), 832–848. 
https://doi.org/10.1044/2022_JSLHR-22-00265 

Regacone, S., Stenico, M., Gução, A., Rocha, A., Romero, A., Oliveira, C. & Frizzo, A. (2015). 

Avaliação eletrofisiológica do sistema auditivo em indivíduos com gagueira 
desenvolvimental persistente. Revista CEFAC, 17(6), 1838–1847. 
https://doi.org/10.1590/1982-0216201517610114 

Rickheit, G. & Strohner, H. (2008). Handbook of Communication Competence. De Gruyter 

Mouton.  

Riley, G. (2009). SSI-4: Stuttering Severity Instrument (4th ed.). Pro-ed.  

Riley, J., Riley, G., & Maguire, G. (2004). Subjective Screening of Stuttering severity, locus of 

control and avoidance: Research edition. Journal of Fluency Disorders, 29(1), 51–
62. https://doi.org/10.1016/j.jfludis.2003.12.001 

Ritto, A., Juste, F., & Andrade, C. (2015). Impacto do uso do SpeechEasy nos parámetros 
acústicos e motores da fala de indivíduos com gagueira. Audiology - Communication 
Research, 20(1), 1–9. https://doi.org/10.1590/S2317-64312015000100001440 

Rohani Ravari, M. H., Darouie, A., Bakhshi, E., & Amiri, E. (2022). The effect of distance 

delivery of Lidcombe program on the severity of stuttering in preschool children: a single-
subject study. Journal of Rehabilitation, 23(2), 272–289. 
https://doi.org/10.32598/RJ.23.2.3351.1 

Rossi, R., Pinto, J., Arcuri, C., Ávila, C., & Schiefer, A. (2014). Habilidades fonológicas em 
crianças com gagueira. Revista CEFAC, 16(1), 167–173. https://doi.org/10.1590/1982-
021620147012 

Ruscello, D. (2001). Test and Measurements in Speech-Language Pathology. Butterworth-

Heinemann.  

Salgado, A. (2008). Manual Práctico de Tartamudez. Editorial Síntesis. 

70 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
Shapiro, D. (1999). Stuttering Intervention: A Collaborative Journey to Fluency Freedom. Pro-

Ed. 

Shapiro, D. (2011). Stuttering Intervention: A Collaborative Journey to Fluency Freedom (2nd 

ed.). Pro-Ed. 

Sherman, D. (1952). Clinical and experimental use of the Iowa Scale of Severity of Stuttering. 

The Journal of Speech and Hearing Disorders, 17(3), 316–320. 
https://doi.org/10.1044/jshd.1703.316 

Sherman, D. & McDermott, R. (1958). Individual ratings of severity of moments of stuttering. 

Journal of speech-language and hearing research. Journal of Speech and Hearing 
Research. 1(1), 61. doi:10.1044/jshr.0101.61  

Sønsterud, H., Howells, K., & Ward, D. (2022). Covert and overt stuttering: Concepts and 

comparative findings. Journal of Communication Disorders, 99. 
https://doi.org/10.1016/j.jcomdis.2022.106246 

Spurlock, D. J. (1966). An Investigation of the Use of the Semantic Differential for An 

Investigation of the Use of the Semantic Differential for Assessing Reactions to Stuttering 
Behavior Assessing Reactions to Stuttering Behavior. 
https://scholarworks.wmich.edu/masters_theses 

Subasi, M., Van Borsel, J., & Van Eerdenbrugh, S. (2022). The Lidcombe program for early 
stuttering in non-english-speaking countries: a systematic review. Folia Phoniatrica et 
Logopaedica, 74(2), 89–102. S. Karger AG. https://doi.org/10.1159/000517650 

Tarkowski, Z. (2016). A New Approach to Stuttering: Diagnosis and Therapy. Nova 

Biomedical.  

Tichenor, S., Leslie, P., Shaiman, S., Yaruss, J. (2017). Speaker and observer perceptions of 
physical tension during stuttering. Folia Phoniatrica et Logopaedica, 69(4), 180-189.  
DOI: 10.1159/000486032  

Tichenor, S. E., & Yaruss, J. S. (2019). Stuttering as defined by adults who stutter. Journal of 

Speech, Language, and Hearing Research, 62(12), 4356–4369. 
https://doi.org/10.1044/2019_JSLHR-19-00137 

Williams, D. (2023). Stuttering Perspectives: A Journey Through Research, Treatment, 

Controversies, and Personal Accounts. Routledge.  

Wright, L. & Ayre, A. (2000). WASSP: Wright & Ayre Stuttering Self-Rating Profile. Winslow 

Bicester.  

71 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Yairi, E., & Ambrose, N. G. (1999). Early childhood stuttering I: Persistency and recovery 

rates. Journal of Speech, Language, and Hearing Research, 42(5), 1097–
1112. https://doi.org/10.1044/jslhr.4205.1097  

Yairi, E. & Seery, C. (2021). Stuttering: Foundations and Clinical Applications (3rd ed.). Plural 

Publishing.  

Yaruss, J. S., & Quesal, R. W. (2006). Overall Assessment of the Speaker’s Experience of 

Stuttering (OASES): Documenting multiple outcomes in stuttering treatment. Journal of 
Fluency Disorders, 31(2), 90–115. https://doi.org/10.1016/j.jfludis.2006.02.002 

Young, M. A. (1970). Anchoring and sequence effects for the category scaling of stuttering 

severity. Journal of Speech and Hearing Research, 13(2), 360–368. 
https://doi.org/10.1044/jshr.1302.360 

Zebrowski, P. & Kelly, E. (2002). Manual of Stuttering Intervention: Clinical Competence 

Series. Singular Pub Group.  

Zebrowski, P., Anderson, J. & Conture, E. (2022). Stuttering and Related Disorders of Fluency 

(4th ed.). Thieme.  

72 

 
 
 
 
 
 
 
 
 
APPENDIX A: RECRUITMENT FLYERS 

Figure 1. Flyer in English 

Figure 2. Flyer in Spanish 

73 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Figure 3. Flyer in Portuguese 

74 

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
APPENDIX B: CONSENT FORM 

Study Title: Defining the severity of stuttering  
Background and Purpose of the Study  
The purpose of this study is to learn more about how people who stutter and professionals view 
the concept of stuttering severity.  

WHAT YOU WILL DO  
You will be asked to provide answers to a survey about your perspectives regarding the severity 
of stuttering. Your participation in this study will require about 25 minutes.  
POTENTIAL BENEFITS  
Though you will not directly benefit from your participation in this study, your response will 
help clinicians, researchers, and other people who stutter better understand your experiences of 
stuttering.  
POTENTIAL RISKS  
There are minimal foreseeable risks associated with participation in this survey. The primary risk 
is a breach of confidentiality. We will take every precaution to guide your privacy by ensuring 
that your personal information will not be released publicly or shared with anyone. The other 
possible risk is that some of the questions may cause you to feel uncomfortable. You will not be 
required to answer any question that you do not wish to answer.  
PRIVACY AND CONFIDENTIALITY  
Information about you (including name and demographic information) will be kept confidential 
to the maximum extent allowable by law. Data will be stored on a secure, password-protected 
server at MSU. The only people who will have access to this server will be people directly 
involved with the research study and the University’s Institutional Review Board (IRB).  
All survey item responses will be de-identified for analysis, and no personally identifiable 
information will be included in any presentations or publications resulting from this study.  
All data will be collected via the internet and responses will be anonymized. Results of this study 
will be made available to you and anyone who completes this survey. A link will be sent via 
email when the study is completed.  

Your rights to participate, say no, or withdraw 
Participation is voluntary.  
You have the right to say no.  
You may change your mind, discontinue, and withdraw from the study at any time.  
You may choose not to answer specific questions or to stop participating at any time.  

COSTS AND COMPENSATION FOR BEING IN THE STUDY  
There is no cost to you, or compensation provided for this suervey. We appreciate your time and 
your responses so that we can learn more about your perspectives on stuttering severity. 

Contact Information  
If you have concerns or questions about this study, such as scientific issues, or to report an 
injury, please contact the researcher or the faculty supervisor:  
• 

Angelica Bernabe; bernabea@msu.edu  

75 

 
 
 
 
 
 
 
 
• 

Prof. J. Scott Yaruss, PhD, CCC-SLP BCS-F, F-ASHA (Lab Director) jsy@msu.edu  

Michigan State University Spartan Stuttering Laboratory  
1026 Red Cedar Road, Oyer Building, MSU, East Lansing, MI 48824  
If you have questions or concerns about your role and rights as a research participant, would like 
to obtain information or offer input, or would like to register a complaint about this study, you 
may contact, anonymously if you wish, the Michigan State University’s Human Research 
Protection Program at 517-355-2180, Fax 517-432-4503, or e-mail irb@msu.edu or regular mail 
at 4000 Collins Rd, Suite 136, Lansing, MI, 48910  

DOCUMENTATION OF INFORMED CONSENT  
Please select your choice below. You may print a copy of this consent form for your records. 
Clicking “Agree” indicates that:  

- You have read the above information 
- You are voluntarily agree to participate  
- You are 18 years of age or older 
- If you choose to provide your email address, you also agree to receive email notices about 
future surveys from the Spartan Stuttering Laboratory 

76 

 
 
 
 
 
 
 
 
English 

APPENDIX C: SURVEY QUESTIONS 

1.  How would you define "severity" as it relates to stuttering? If you are a person who 

stutters, we are not asking about the severity of your stuttering; instead, we want to learn 
about how you define severity of stuttering. You may choose to initiate your answer with 
the phrase "I define stuttering severity as..."  

2.  Do you think that stuttering severity is made up of different components? If so, please 

list and describe what those components are.  

3.  Do you think that stuttering severity can be affected by different factors? If so, please 

describe what those factors are. 

Spanish 

1.  ¿Cómo definiría la "severidad" en relación a la tartamudez? Si eres una persona con 
tartamudez, no estamos preguntando por la severidad de tu tartamudez; en cambio, 
queremos saber cómo tú defines la severidad. Puede optar por iniciar su respuesta con la 
frase "Defino la severidad de la tartamudez como..." 

2.  ¿Cree que la severidad de la tartamudez está constituida por diferentes componentes? En 

ese caso, por favor, enumere y describa cuáles son. 

3.  ¿Cree que la severidad de la tartamudez puede ser afectada por diferentes factores? En 

caso sea afirmativo, por favor, describa cuáles son esos factores. 

Portuguese 

1.  Como você definiria "severidade" no contexto da gagueira? Se você é uma pessoa que 
gagueja, não estamos perguntando sobre a severidade da sua gagueira; em vez disso, 
queremos saber como você define a severidade da gagueira. Você pode optar por 
começar sua resposta com a frase "Eu defino a severidade da gagueira como..." 
2.  Você acredita que a severidade da gagueira é constituída por diferentes componentes? 

Em caso afirmativo, por favor, liste e descreva quais são esses componentes. 

3.  Você acredita que a severidade da gagueira pode ser afetada por diferentes fatores? Em 

caso afirmativo, por favor, descreva quais são esses fatores. 

77