The Valsalva Stuttering Network



By William D. Parry, Esq., M.A., CCC-SLP

A licensed Speech-Language Pathologist and Trial Lawyer, Founder and Chapter Leader of the Philadelphia Area Chapter of the National Stuttering Association, and former member of the National Stuttering Association Board of Directors

NOTE: The following article was written prior to my recent clinical trials of Valsalva Control Therapy, which produced important refinements to the Valsalva Hypothesis and improved therapy techniques.  Therefore, please see my new articles:


Valsalva Control Stuttering Therapy: A Brief Introduction, and


New Insights and Tools To Beat Stuttering Blocks, based on my presentation at the National Stuttering Association conference in Ft. Worth, Texas, on July 7, 2011, including the results of my first clinical study of Valsalva Control Therapy and videos from my current trial of intensive Valsalva Control Therapy.

Why is stuttering usually worst when the words are most important? This article shows how a natural bodily function - the Valsalva mechanism - may turn our efforts to speak into the very blocks we are trying so hard to avoid. It explains how a combination of physical and psychological factors may trap us in a "Valsalva-Stuttering Cycle" - a vicious circle that may trigger and perpetuate stuttering, as well as sabotaging our efforts at fluency maintenance.

This article is adapted from a presentation given by the author at the World Congress for People Who Stutter, in Linköping, Sweden, on July 29, 1995. It provides a brief introduction to the "Valsalva Hypothesis."  (For further information, see Understanding and Controlling Stuttering: A Comprehensive New Approach Based on the Valsalva Hypothesis. )

NOTE:  This article discusses stuttering in its most common form, often called "persistent developmental stuttering."  It may not apply to other types of disfluencies.

I. Introduction

It is a great honor to be invited to speak at this World Congress in Sweden. As you know, I come from the United States, where I lead the Philadelphia Area Chapter of the National Stuttering Project. By profession, I am a lawyer. But the great obsession of my life has been the mystery of stuttering - a condition with which I have struggled since I was four years old.

Over the years, I submitted to a wide range of therapies, without lasting success. Finally, about fifteen years ago, I gave up on therapy altogether and began doing my own research into the problem.

It seemed obvious that my speech mechanism was basically all right. Back in high school, I had taken elocution lessons, and had learned to act out roles in front of an audience with perfect fluency. However, in other situations, it seemed as if a powerful force clamped down on my speech like a vise, causing me to block. My problem was not any lack of ability to speak, but rather an interference with that ability. I suspected that the interference was physiological in nature, but that it might be activated by psychological factors.

Diagram of the Valsalva mechanismAfter extensive review of medical literature, consultations with professional researchers, and personal experimentation, I believe that I have found the force behind that interference. It is a normal bodily mechanism that we instinctively use every day, without even thinking about it. It is called the Valsalva mechanism. The Valsalva mechanism is a neurologically coordinated team of muscles throughout the body which act together in the performance of a Valsalva maneuver.

II. The Valsalva Maneuver

A. Demonstration

You can experience what a Valsalva maneuver is by performing the following exercise. Stand up. Curl your fingers, and link both hands together in front of your chest. Take a deep breath. Now try to pull your hands apart, as hard as you can, without letting go. Pull really hard.

What do you notice while you are pulling? Do you notice how the muscles in your chest and abdomen tighten up? What do you notice about your throat? Do you notice that your throat closes up?

Try the exercise again. Pull really hard and see if you can feel it. Do you notice that, the harder you pull, the more tightly your throat closes? This closure occurs in the same place that your voice is produced - the larynx.

Now try the same exercise again. This time, start by putting your lips together and pretend you are going to say a p sound. Now pull your hands apart as hard as you can. What do you notice about your lips? Do you find your lips pressing tightly together?

Now see what happens when you press the tip of your tongue to the ridge behind your upper front teeth, and pretend you are going to say the t sound. Take a deep breath and start pulling. Do you feel the tip of tongue pressing forcefully? Do these forceful closures feel familiar?

You were performing a Valsalva maneuver. It takes its name from Anton Maria Valsalva, an Italian anatomist who lived from 1666 to 1723. Although it has been known to medical science for more than 200 years, it has been almost totally ignored by speech pathologists.

Diagram of a Valsalva Maneuver

B. The Function of the Valsalva Maneuver

The purpose of a Valsalva maneuver is to increase air pressure in the lungs, in order to help a person exert physical effort or force things out of the body.

This is how it works: Your abdominal muscles tighten up, squeezing the intestines and organs in the abdominal cavity, so that they press upward against the diaphragm - the dome-shaped muscle that separates the abdominal cavity from the chest cavity. This causes the diaphragm to bulge upward, compressing the chest cavity. Certain chest muscles also tighten to bring the rib cage down, which compresses the chest cavity even more.

Meanwhile, the larynx is neurologically programmed to close tightly around the upper airway to keep the air in the lungs from escaping. The more the abdominal muscles squeeze, the greater the air pressure becomes in the lungs, and the tighter the larynx closes. The larynx is doing one of the basic tasks for which it is designed. It is called effort closure.

We are all familiar with the other function of the larynx, which is phonation. That occurs when the vocal folds in the larynx are brought gently together across the airway to make the sound of our voice. But when the larynx performs effort closure during a Valsalva maneuver, it behaves very differently. The entire inside of the larynx closes tightly, like a fist, to block the air completely. As we saw in our exercise, the lips and tongue can also do this job. If for some reason your lips or tongue are blocking the airway when you start a Valsalva maneuver, they will be recruited to continue the closure. They will automatically press harder and harder to keep the air from escaping.

Cross-section of the larynx, comparing phonation and effort closureWhy does the body do this? The increased lung pressure created by a Valsalva maneuver helps us to exert physical effort more efficiently. Have you ever noticed how a weight lifter "holds his breath" as he strains to raise a heavy bar bell over his head? He is doing a Valsalva maneuver. The air pressure in his lungs keeps his chest and shoulders firm and rigid, giving greater support to his arms. In this way, he can direct all his energy toward lifting the weight. Otherwise, some of that energy would be wasted as his chest and shoulders sagged.

The Valsalva maneuver also helps us to force things out of the body. The most common examples are defecation, urination, and childbirth. In these activities, the air pressure helps to stabilize the diaphragm, so that the abdominal muscles can squeeze things out of the abdominal cavity more efficiently. When defecation is intended, the rectal and anal muscles relax, permitting the bowel movement to be expelled. However, when defecation is not intended - for example, when we are lifting weights - these muscles tighten up to prevent an accidental evacuation of the bowels.

All these muscles comprise the Valsalva mechanism. They are linked together as a "team" by our nervous system. They are neurologically coordinated to contract at the same time, and with the same relative degree of force, during a Valsalva maneuver.

C. Similarities with Stuttering

As soon as I learned about the Valsalva maneuver, I was struck by its similarity to the forceful closures that occur during stuttering blocks. The effort closure of the larynx felt just like what happened when I blocked on an initial vowel sound, as in "uh-uh-uh-uh-airplane."

To check this out, I had a laryngologist put a fiber-optic tube down my throat to take video pictures of my larynx. Indeed, we found that both types of closure looked exactly the same. The forceful closures of my lips and tongue were also the same as when I blocked on consonants.

I suddenly realized what I had been doing all those times when I blocked. I had been doing a Valsalva maneuver.

III. Clues to the Paradoxes of Stuttering

This realization was the beginning of a new understanding of stuttering, which changed my life. It suggested answers to some of the most frustrating paradoxes of stuttering that had bedeviled me for so many years.

For example, why do we tend to stutter more in some situations than in others? We tend to be more fluent when talking to ourselves, or when saying words that are not important. Stuttering generally increases when we are speaking to authority figures or other people whom we feel we have to please or impress. When certain words must be said exactly right, like saying our name or the punch line of a joke, stuttering usually hits the hardest.

In my own experience, I always found it easier to say the wrong word, whatever it was, than the precise word that was most appropriate. In answering the telephone, I could not simply say "Hello." In order to get it out, I would have to say "Yes, hello." But one day when I picked up the telephone, the person on the other end immediately said, "Hello, is this Bill Parry?" Suddenly I could not say "yes." Instead I had to say, "Hello, yes, this is Bill Parry."

The Valsalva mechanism may help to explain this. All these examples involve circumstances in which we feel that the words themselves are especially important, or we anticipate that speaking will be difficult. These are precisely the moments when we may feel that some kind of extra effort will be needed. Therefore, these would be the times we would be most likely to activate the Valsalva mechanism - which is instinctively used when we exert ourselves.

Another paradox of stuttering is the excessive amount of force and effort we use in trying to speak. Fluent speech actually requires very little physical effort. The articulation of words is accomplished by gentle movements of the lips and tongue, which touch lightly and then relax quickly. In contrast, when we stutter, our lips, tongue, or larynx press much harder and longer than speech requires. Paradoxically, our effort to get the words out becomes the very obstacle that we are trying so hard to overcome.

I myself wrestled with this paradox for most of my life. For example, I knew that when I wanted my car to go forward, I should step on the gas - not stomp on the brakes. But when it came to speaking, that, in effect, is exactly what I was doing - pressing harder and harder with my lips or tongue, and wondering why my speech wasn't going forward. No matter how I tried intellectually to recognize the futility of such effort, I found myself at a loss to control it. For some reason, using force and building up air pressure felt like the right thing - the only thing - to do, even though it blocked my speech more than ever.

The Valsalva mechanism answers this riddle. It is a bodily mechanism designed to do exactly what happened when I blocked. A Valsalva maneuver may feel like the right thing to do, because it is our instinctive reaction when we exert physical effort or try to force things out of the body.

IV. The Valsalva Hypothesis

These observations led me to formulate a theory, which I call the Valsalva Hypothesis. Briefly stated, my hypothesis suggests that stuttering blocks may involve a neurological confusion between speech and the Valsalva mechanism. Such confusion would tend to occur when we anticipate the need to "try hard" to speak properly or to force the words out.

A. Neuromotor Tuning

How might such confusion between speech and the Valsalva mechanism take place? Scientific studies show that all physical activity, including speech, is preceded by a neurological tuning of the motor neurons that control the muscles to be used in the particular movement. The tuning makes some neurons more excitable, and others less excitable, to the triggering impulse that actually starts the movement.

In effect, the brain says to some neurons, "Pay attention! Get ready to contract your muscles when the next command comes!" To others it says, "Relax. Disregard the next command, because it's not meant for you." A fraction of a second later, the triggering command comes down the line. The neurons and their muscles either respond or don't respond, depending on their level of excitability.

You can demonstrate this principle yourself, by playing this trick on your friends. First show them how, by contracting different muscle groups, you can make your hand into a fist, or do other things such as pointing a finger. Then till your friends to make a fist, as fast as they can, when you say "Now!"

First alert them by saying, "Get ready to make a fist." (That is like the tuning signal.) Then say "Now!" (which is like the triggering signal) as you make a fist yourself. "Not bad," you tell them, "but you're not doing it fast enough. Let's try again."

Repeat this exercise a few times, so that everyone has gotten into the habit of making a fist as fast as they can. Then, after again instructing them, "Get ready to make a fist," suddenly say, "Point," and point your finger.

I have found that most people reflexively make a fist instead - because that is what their nerves and muscles are neurologically prepared to do. Likewise, when we feel that speaking will require extra effort, our body might become neurologically tuned for a Valsalva maneuver rather than for speech.

B. The Stuttering Block

Let's see how Valsalva tuning might result in the forceful closures of a stuttering block.

Imagine that you are at a dinner party and would like someone to pass the potatoes, which are at the other end of the table. If you were a fluent speaker, you would simply say, "Pass the potatoes, please." Your chest muscles and diaphragm would relax, releasing a gentle flow of air through your larynx and mouth. To form the p, your lips would close, momentarily blocking the airflow in order to build up a little air pressure. Then the lips would relax, releasing a puff of air, which makes the p sound.

How do the lips know when to open? One possible explanation is that the increase in air pressure is sensed by pressure-sensitive nerves (called mechanoreceptors) found in the lower part of the larynx and elsewhere along the respiratory tract. They would send impulses to the brain, indicating the amount of air pressure. When just enough pressure has been built up, the brain would signal the lips to let go. That is what is supposed to happen. Now let's see what might go wrong, according to the Valsalva Hypothesis.

First, let us assume that you have been blocking on your p's lately. When you see that a p word is coming, your brain anticipates that saying the word will be difficult. It decides that extra effort will be needed and tunes up the Valsalva mechanism. All the nerves and muscles of the Valsalva mechanism are now geared up to perform a Valsalva maneuver the instant a triggering stimulus comes down the line.

One kind of triggering stimulus could be the increase in air pressure that normally occurs during articulation - for example, when you close your lips to say the p sound. Normally, this increased air pressure would tell the lips to open. However, if the Valsalva mechanism is overly excitable, it could have just the opposite effect. The increased air pressure could be misinterpreted as the beginning of a Valsalva maneuver - triggering a reaction by the entire Valsalva mechanism. This would stimulate the lips to close more tightly, to keep the air from escaping. The more you contract your abdominal muscles and build up air pressure, the tighter your lips will close. Suddenly, you find yourself in a stuttering block, which automatically gets worse the more you try to force through it.

Similar types of blocking might be stimulated whenever articulation involves an obstruction of airflow by the lips, tongue, or larynx, causing increased air pressure. The Valsalva hypothesis might therefore explain why stuttering is often reduced when the speaker uses a "gentle onset" of voice and "light contacts" in articulation, or starts speech with a stream of "passive airflow." Such methods would tend to avoid abrupt increases in air pressure, and thereby reduce the likelihood of a Valsalva maneuver.

C. Valsalva Tuning and Phonation

Valsalva tuning may also contribute to another problem that stutterers have, which is difficulty or delays in phonation - the making of voiced sounds. Some experts have suggested that these delays may interfere with the flow of speech, thereby contributing to stuttering.

Difficulty in phonation is a factor that people often overlook. For example, if I said "puh-puh-puh-puh-potato," most people would assume that I was having trouble pronouncing the p sound. But that is obviously not true, because I just said the p perfectly well several times. My real problem may been in moving on to the vowel sound that followed it. Valsalva tuning may be one of the problems.

Scientific studies have found that, before the larynx makes a voiced sound, a process called prephonatory tuning must occur. However, if our body is tuned for a Valsalva maneuver, the larynx will be prepared to perform effort closure instead. It will not be ready to phonate. Therefore, even if the larynx does not actually close, phonation may be delayed as we struggle to re-tune the larynx to make the proper sound.

This may also help us understand why we stutterers are usually fluent when we sing. Have you ever wondered why that might be? When we sing, our mind concentrates on the melody, rather than trying to force the words out. Therefore, our larynx is constantly tuned for phonation, and is always ready to phonate at the proper time.

V. Origins and Perpetuation of Stuttering

A. Early Disfluencies

Let us now consider how the confusion between speech and the Valsalva mechanism might have started.

I don't think that the Valsalva mechanism causes a child's earliest disfluencies. In the beginning, a child's disfluencies are usually effortless, whole-word repetitions, without the force and struggle that we later see. Those disfluencies may arise from a number of different factors, such as delays in the neurological development of speaking skills, emotional stress, or excessive demands for good speech placed upon him by adults. The underlying factors may be different for each individual.

The one thing these factors have in common, however, is that they tend to make speech more difficult. The child may perceive this difficulty as a kind of "verbal constipation." Since the child is already accustomed to using the Valsalva maneuver when exerting effort or expelling bowel movements, he may instinctively assume that words can be forced out in the same way.

This display of effort could also be the child's way of telling his parents: "You can't punish me for stuttering. Look how hard I'm trying to please you!"

B. The Valsalva-Stuttering Cycle

Once the Valsalva mechanism gets into the act, stuttering takes on a whole new dimension. Soon the child is caught in a vicious cycle that may perpetuate stuttering even after the cause of his original disfluency has disappeared. I call this the "Valsalva-Stuttering Cycle." Let us see how it might work.

Step 1: The Anticipation of Difficulty. We begin with an expectation or feeling that speech will be difficult, or that particular words will be hard to say. This attitude may be based on any number of factors, depending on the individual and the circumstances.

Step 2 : The Urge To Try Hard. Because we expect difficulty in speaking, we may then instinctively feel that extra effort will be needed to overcome the obstacles. We may unconsciously treat the words as if they were "things" that can be forced out with the same kind of physical effort that is normally assisted by the body's Valsalva mechanism.

Step 3: Valsalva Tuning. The brain responds by neurologically preparing the larynx and other parts of the body's Valsalva mechanism to perform a Valsalva maneuver (in which air pressure is built up by forcefully closing the larynx or mouth while the chest and abdominal muscles squeeze the chest cavity), in the mistaken belief that this may help to force the words out.

Step 4: Vocal Delays and Forceful Closures. As we have just discussed, there may be difficulty or delays in phonation, because the larynx is neurologically prepared to perform effort closure rather than phonation. Valsalva tuning may also lead to excessively forceful closures of the mouth or larynx during articulation, resulting in the blocking of speech.

Step 5: Avoidance Behavior. In an attempt to avoid, postpone, or hide our blocks, we may resort to a wide variety of behaviors. These might include hesitations, repetitions, the use of starters, fillers, and other unnecessary words and sounds, word substitutions, breathing irregularities, teeth gnashing, and other tactics.

Step 6: Mental Reaction to Stuttering. We may interpret our stuttering as confirming our original belief that speech is difficult, or that particular words are hard to say. We may think, "I was right. That was difficult. If I didn't try hard, I probably never would have been able to say it. The next time I'll have to try even harder." We may be left with the false impression that Valsalva tuning, the use of force, and other stuttering behaviors were eventually successful in getting the words out. This perception may reinforce the very attitudes and behaviors that will promote stuttering in the future.

As we go round and round the Valsalva-Stuttering Cycle, we learn to force more and more, and our rut becomes ever deeper and harder to escape. Using the Valsalva mechanism to force out words instinctively feels like the right thing -- the conscientious thing, the only thing -- to do, even though in reality it interferes with normal speech.  We are caught in the "Valsalva Trap."

C. Effect on Brain Development

Continuation of this behavior during childhood may have lasting neurological consequences. Constant repetition of the Valsalva-Stuttering Cycle might cause the development of strong nerve pathways linking speech to the Valsalva mechanism. Meanwhile, the pathways for fluent speech might remain underdeveloped.

In this way, the tendency to confuse the Valsalva mechanism with speech may become permanently "wired" into the stutterer's brain. Consequently, it is not surprising that recent studies, using PET scans and the like, have found that stutterers' brains function differently during speech than those of non-stutterers.

VI. Valsalva Control

Understanding the Valsalva mechanism may also help us find more effective ways to improve our fluency. Today we are confronted by a wide range of competing therapies, fluency devices, and techniques - many appearing to be totally different and even contradictory to one another in their approaches.

However, when I analyzed all these approaches, I came to a startling conclusion: To the extent that they were successful, they all could be explained in terms of the effect they had in disrupting one or more of the steps in the Valsalva-Stuttering Cycle. In various ways, they each reduced to some extent the stutterer's tendency to activate the Valsalva mechanism during speech. Unfortunately, the existing therapies seemed relatively inefficient and incomplete, because they failed to deal directly with the Valsalva mechanism itself.

I suspect that this failure to cope with the Valsalva mechanism may be one factor behind the great tendency for people to relapse after successfully completing a fluency program. Such a person might inadvertently activate his Valsalva mechanism while "trying hard" to use his fluency technique. Once that happens, all attempts to use fluency techniques may prove futile. Suddenly the person might find himself back in the grip of stuttering, without any idea of how it happened.

Based on my research, I developed my own experimental, self-help therapy program, which I call "Valsalva Control." Its objective is to control the Valsalva mechanism through both psychological and physical means to reduce the likelihood that it will interfere with our natural speaking ability. I developed or adapted a number of relaxation, breathing, and speaking exercises designed to relax or "tune down" the Valsalva mechanism.

Among other things, I learned how to short-circuit stuttering blocks by relaxing my abdominal muscles, so as to reduce the build-up of air pressure, rather than trying to force the words out. In addition, I used certain phonation exercises to help "tune up" my larynx for phonation.

Every morning, I began the day by spending one-half hour doing a special exercise routine, to get myself properly tuned for speech. Over several weeks, my fluency gradually improved. After a few months, the improvement was dramatic, and my gains have now lasted for ten years.

This approach to Valsalva Control is described in detail in my book, Understanding and Controlling Stuttering: A Comprehensive New Approach Based on the Valsalva Hypothesis.

VII. Conclusion

The ideas I have shared with you today, while promising, must still be subjected to considerable research before they can be scientifically verified. Furthermore, I realize that the approaches that worked for me may not be the "answer" for everyone. Because stuttering is such a personal matter, the only "answer" that really counts must be discovered by each individual who stutters.

Nevertheless, I feel that by understanding the Valsalva mechanism, we can free ourselves from a lot of frustration and physical struggle in our attempt to speak. As I see it, the goal of self-help should not be the attainment of perfect fluency - for that is unrealistic, unnecessary, and ultimately self-defeating. Instead, I think our objective should be to make our speech easier and more enjoyable, so we can more freely communicate and interact with other people.

That has been my approach in Valsalva Control - not to expend a lot of effort in monitoring my speech, but to relax and have fun talking.

Copyright © 1997, 2010 by William D. Parry


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).  For further information, e-mail him at

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



Stuttering Therapy and Counseling:

The Valsalva-Stuttering Network:

Beating Stuttering Blocks:
Stuttering and the Law:


The Second Edition (2000) (5th Printing updated in 2009) of Understanding and Controlling Stuttering may be ordered from the National Stuttering Association or

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: 8/12/2011