The Valsalva Stuttering Network

Reducing Stuttering Blocks by Controlling

the Body's Valsalva Mechanism

by William D. Parry, J.D., M.A., CCC-SLP

 Presentation for the International Stuttering Association's

 9th World Congress for People Who Stutter

Buenos Aires, Argentina - May 18, 2011

 Copyright © 2011 by William D. Parry


            My name is William Parry.  I am a speech-language pathologist from the United States. 

            For most of my life I myself struggled with stuttering.   After decades of failed therapies, I found my own way to understand and overcome my stuttering in the early 1980’s, using an approach that I call “Valsalva Control.”  It enabled me to pursue a successful career as a trial lawyer.   Since then, I have been active in the National Stuttering Association in the United States, led stuttering support group meetings, shared my ideas at workshops, and written a popular book on stuttering. 

I am now pursuing my second career – that of a professional speech-language pathologist – in the hope of furthering the understanding and treatment of stuttering.  Over the past nine months I have been conducting a Multiple-Subject Case Study of the Effect of Valsalva Control Therapy on Stuttering Blocks in Adults with Persistent Developmental Stuttering.  I will be sharing the promising results of this the study with you today.

However, I would like to begin by outlining my present beliefs regarding the nature of stuttering and stuttering blocks.

Persistent Developmental Stuttering

            First, I want to be clear as to what I mean by “persistent developmental stuttering.”  


“Developmental stuttering” usually begins in childhood and is not associated with brain damage.


It is “persistent” if it continues into adulthood.


It is basically a speech problem rather than a language problem.  The person knows exactly what he or she wants to say, but is sometimes blocked when trying to say the words.


The person is able to talk fluently some of the time, and stuttering severity may vary depending on the speaking situation.

Understanding Stuttering

            Stuttering is a multi-faceted condition influenced by many factors, depending on each individual.    However, I believe that the best way to understand and treat stuttering behavior is to view it not in terms of “fluency” but rather in terms of effort.

The Mechanism of Stuttering Blocks

I believe that the underlying mechanism for stuttering blocks boils down to the following:  a neurological confusion in the motor programming of the larynx, in which effort is substituted for phonation of the vowel sound in specific syllables.

The Real Problem Is the Vowel

            Most people assume that stutterers have trouble saying initial consonants.  However, these sounds are not the real problem.  For example, a person repeating /p/ in “puh-puh-puh-Peter” or prolonging the /s/ in “S-s-s-s-s-sam” or the /m/ in “M-m-m-mary” is actually saying the /p/, the /s/, and the /m/ perfectly well.  In each case, the real problem is the speaker’s difficulty in producing the vowel sound that follows. 

Stuttering and Phonation

            There is ample evidence that stuttering blocks may involve interference with phonation.  Consider the following:


Persons who stutter have no trouble silently mouthing their words or whispering.  Therefore, stutterers’ articulation does not seem to be impaired.  


Stuttering does not occur until the person adds phonation


The problem is not phonation in general, because the stutterer phonates when prolonging or repeating voiced consonants like /m/, /n/, /r/ and /l/. 

However, when he gets to the vowel sound –


He hits a “brick wall.” 

            Therefore, the problem must be specific to phonation of the vowel sound of the particular word or syllable in question. 

Motor Programming

            This phenomenon can be understood in terms of motor programming.


                Before any bodily movement can occur, the brain must create a motor program for the muscles involved.  The same is true for speech.  A process called prephonatory tuning must prepare the laryngeal muscles to bring the vocal folds together properly before phonation can occur.  However, phonation is not the only function of the larynx. 

The Valsalva Mechanism


         The larynx is also involved in the exertion of physical effort as part of the body’s Valsalva mechanism.   The Valsalva mechanism consists of the larynx and other muscles throughout the body, including the abdominal and chest muscles. 


          These muscles are neurologically programmed to build up air pressure in the lungs by means of a Valsalva maneuver. 


           During a Valsalva maneuver, both the vocal folds and false vocal folds close tightly to block the airway.  This laryngeal function is called effort closure.

            Meanwhile, the abdominal and chest muscles contract in order to increase the air pressure in the lungs.  The more they squeeze to increase air pressure, the more tightly the larynx closes to hold the air in.

Instances of Valsalva Maneuvers

            The purpose of the Valsalva maneuver is to stiffen the trunk of the body so that physical effort can be exerted more efficiently.  We instinctively perform these maneuvers every day – usually when lifting, pushing, or pulling heavy objects and when bearing down to make bowel movements. 

          The Valsalva maneuver may also be activated as part of the “fight or flight” response to fearful situations.

Valsalva and Speech

But what might happen if the Valsalva mechanism becomes involved in the effort to speak – either in response to the anticipation of difficulty or as a reaction to fearful speaking situations?  

Activating the Valsalva mechanism might instinctively feel like the right thing to do, but it could interfere with speech in at least two ways:


By promoting forceful closures of the mouth or larynx to build up air pressure; and


By programming the larynx for effort closure rather than preparing it to phonate the vowel sound.

Effort Inserted at Vowel Position

            The vowel is the natural place to insert the motor program for effort, because it’s the heart of the syllable and has the most energy.

Possible Effects of Weakness in Motor Programming

            Numerous studies have suggested that persons who stutter may have weaknesses in parts of the brain that put together the neurological programs for speech and other fine motor skills. 


These weaknesses may contribute to a person’s feeling that speech is difficult and requires effort.


They might also make a person’s motor programming for speech susceptible to interference. Such interference could be precipitated by stress, anxiety, and other emotional triggers, which would account for the variability of stuttering.

Anatomy of a Block on “Peter”

            In analyzing how a block might occur, let’s use the name “Peter” as an example.  The motor program for “Peter” should have phonation on the “ee” (/i/) and the “er," which can be represented like this:

            But, because Peter anticipates that saying his name will be difficult, his brain inserts a motor program for exerting effort where the “ee” should be, which can be shown like this:


            Without the motor program for the vowel sound, Peter can’t get past the /p/ sound to say his name.  He feels as if there is a “brick wall” that requires force to break through.

            Peter may try to force through the block by building up air pressure, as in a Valsalva maneuver, while closing his lips tightly on the /p/, like this:


            This effort may instinctively feel like the right thing to do, but the more he forces, the tighter his lips close to resist the air pressure. 

            Or Peter might forcefully repeat the initial consonant, like this:

as he waits for the vowel sound to be programmed.  Notice that the “uh” following the /p/ is not the proper vowel sound.  It is basically just a grunt, like you might make when lifting weights. 

Prolongations & Initial Vowels

            When the beginning consonants do not completely block airflow, the result may be a prolongation of the sound, such as:

          In words that start with vowels (such as “apple”), the block may focus on the laryngeal closure or “glottal stop” (/§/) that commonly occurs just before the vowel when the speaker does a “hard onset.”  This may result in a prolonged laryngeal block or a repetition of grunts, like “Ɂuh-Ɂuh-Ɂuh-Ɂuh.” 

Reinforcement of Effort Programming

            Fixation on the initial consonants creates the false impression that these sounds are causing the speaker to block, and that it’s hard to say words beginning with these sounds.  This expectation of difficulty causes the brain to program the larynx for effort, resulting in the very blocks that the speaker feared.

Use of Effort To Reduce Anxiety

            Valsalva programming may also be reinforced through the use of effort to reduce anxiety.  All the participants in my study reported that, to some degree, using effort helped them feel less anxious.  This was particularly true for participants whose parents were critical of their stuttering.  Using effort may have become a way to show how hard they were trying to please. 

Using effort was reinforced because of its short-term benefit in reducing anxiety, even though it perpetuated stuttering. 

            Understanding this dynamic was crucial to reducing the effort used in speaking situations.

Valsalva Control Therapy

            The purpose of Valsalva Control Therapy is to promote easy, natural, resonant speech by eliminating interference from the body’s Valsalva mechanism and the urge to exert effort. 

            Its elements include education, Valsalva relaxation, exercises in phonation, strengthening vowel production, various speaking exercises, role playing, speaking situation hierarchies, attitude changing, and individualized counseling.

            Valsalva Control intentionally does not emphasize fluency, because any effort to “stop stuttering” would tend to activate the Valsalva mechanism and be self-defeating.  Instead, the goal is to communicate in an easy, effortless, and enjoyable way.  

          Likewise, the participants’ reactions to outside speaking situations are analyzed and discussed in terms of their urge to exert or display effort, rather than whether or not they stuttered.

Handling Anticipated Blocks

            Among other things, clients are taught not to force through anticipated blocks.  Instead they should stop, take a breath, relax their abdomen as they exhale, and focus on phonating the vowel sound.  We have found that pulling on clasped fingers may help to facilitate vowel production.

Clinical Trial – Phase I

            In July 2010, I began the first phase of my clinical trial on the effectiveness of Valsalva Control Therapy. 

           The participants were five English-speaking males, ages 21-31, with moderate-to-severe developmental stuttering.  Appropriate consents and authorizations were obtained.

           Therapy was administered in 25 weekly one-hour sessions, plus daily 30-minute exercise routines and other homework assignments.  All sessions were conducted by video conferencing using Skype™ and video recorded.

During the course of the study, the therapy evolved as new materials and exercises were added.

Average Results for All 5 Participants

            The following are the average results for all five participants in the study. 

% Syllables Stuttered in Oral Reading

The first graph shows the reduction in percentage of syllables stuttered in oral reading for all five participants.  The black line shows a beginning average of 8.86 per cent stuttered syllables, reduced to an average of 1.26 per cent after 24 weeks – a reduction of about 86 per cent.

Stuttering Severity Scores (SSI-4)

            The next graph shows the Stuttering Severity Scores for the five participants, based on the Stuttering Severity Instrument-4.  As shown by the black line, the average score was reduced by 61 per cent, dropping from “Moderate” to “Very Mild.”

OASES Scores at 0, 8, 16 & 24 Weeks

The next graph shows the overall impact of stuttering as measured by the OASES questionnaire – the “Overall Assessment of the Speaker’s Experience of Stuttering.”  This test has a minimum score of 1.00 and a maximum score of 5.00.  As shown by the black line, the average impact was reduced from “Moderate-Severe,” to “Mild-Moderate” – an average reduction of 50.63 per cent.

“Easy and Effortless” Self-Reporting

            Each week the participants were asked to report how easy and effortless their speech had felt to them in various speaking situations.  Participants ranked the amount of effort on a scale of 1 to 9, with 1 being “Very easy and effortless” and 9 being “Very difficult.”  

            The next graph shows the average progress in “easy and effortless speech.”  The red line represents the average “most difficult” experience, the green line represents the average “easiest” experience, and the blue line represents the average rating of speech in general.  As you will see, the average effort in general was cut approximately in half, from around 5 down to about 2.6.

Participants’ Evaluation of Program

            At the end of 24 weeks, the participants were given a questionnaire to evaluate the therapy they had received.   They were asked to rate how strongly they agreed or disagreed with the following statements.


5 out of 5 participants “Strongly Agreed” with these statements:

o   The explanations about Valsalva-Stuttering accurately described my own experience of stuttering.

o   The program helped me to understand my stuttering better.

o   I will continue to use Valsalva Control in the future.

o   I learned skills and insights that will help me to continue to improve my speech on my own.

o   I would recommend Valsalva Control to other people who stutter.


4 out of 5 participants “Strongly Agreed” and one “Somewhat Agreed” that:

o   The program made speaking more enjoyable for me.

o   Overall, I was satisfied with the Valsalva Control program.


3 out of 5 participants “Strongly Agreed” and two “Somewhat Agreed” that:

o   The program made my speech easier and less effortful.

o   The program reduced the frequency of my stuttering blocks.

o   The program helped to reduce my anxiety about speaking.

o   I find it easy to use Valsalva Control in everyday speaking situations.

o   My speech sounds and feels natural when I use Valsalva Control.


All participants who had previous therapy “Strongly Agreed” that:

o   Valsalva Control helped me more than any other therapy I have had.

Individual Case Study: DM

            Now let’s look at one of the individual case studies.

            DM was a 27-year-old male trial lawyer who began stuttering when he first started to talk.  His previous therapies included several years of speech therapy in public schools, delayed auditory feedback (which was not effective outside of the clinic), two weeks of precision fluency shaping at the Hollins Institute (which was followed by a relapse within 6 weeks), and the Speech Easy device (which was not effective). 

DM’s Results (including 2-week follow-up)

This table shows a comparison of DM’s individual results before and after therapy.  As you will note, his percentage of syllables stuttered in oral reading dropped from 9.70 per cent to zero.  He began with a Stuttering Severity Instrument Total Score of 29, considered “Moderate,” which dropped to 8, which is in the “Normal” range – for a reduction of 72.41 per cent.  His overall impact of stuttering, as measured by the OASES test, dropped from 4.01, which is considered “Severe,” to 1.66, which is considered “Mild-Moderate” – a reduction of 78 per cent.  His Fluency Self-Report was also greatly improved.


          Based on this preliminary trial, Valsalva Control appears to be a valid approach to understanding and treating stuttering, while preserving the individuals’ own natural-sounding speech.  

          Furthermore,  Valsalva Control provides practical insights and tools for persons to make further progress on their own.  This is important, because deeply entrenched nerve pathways for any kind of behavior, including stuttering, often take a very long time to change.

            Three of the five participants showed dramatically reduced stuttering both in and outside of therapy sessions.  The two other participants reported less success in transferring Valsalva Control to outside speaking situations, possibly due to anxiety issues.   They may have needed more intensive therapy than weekly Skype sessions.

Future Therapy Trials

            The late addition of new therapy materials, exercises, and techniques appeared to accelerate the progress of some participants.  Therefore, I am planning a more intensive Phase Two clinical trial to determine whether these modifications to Valsalva Control will help to reduce stuttering more quickly and effectively.

            If you would like further information about Valsalva Control Therapy, I invite you to review the paper that I submitted, which is contained on your C.D. of the Congress. and to visit my website, “The Valsalva-Stuttering Network,” at

            Thank you.


Contact Information:


 William D. Parry, Esquire, CCC-SLP

A licensed speech-language pathologist and trial lawyer, offering stuttering therapy and counseling (including Valsalva Control stuttering therapy) in person in Philadelphia and over the Internet via webcam (subject to applicable law). 

Office: 1608 Walnut Street, Suite 900, Philadelphia, PA 19103
Office phone: 215-735-3500    Mobile phone: 215-620-6792




Stuttering Therapy and Counseling:

The Valsalva-Stuttering Network:
Beating Stuttering Blocks:
Stuttering and the Law:


Valsalva Control Stuttering Therapy is a new approach to improving fluency by controlling the physiological mechanism that may be causing stuttering blocks. For further information on Valsalva Control Therapy, visit Stuttering Therapy and Counseling at


The Revised and Expanded Third Edition of Understanding and Controlling Stuttering (2013) may be ordered from the National Stuttering Association.

For information concerning stuttering self-help and support, please contact:

National Stuttering Association
119 West 40th Street, 14th Floor, New York, NY 10018
Telephone: (800) 364-1677 or (800) WE STUTTER
Fax: (212) 944-8244


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Last revised: 5/1/13