Stuttering as a Voice Problem

by William D. Parry, Esq., CCC-SLP

Copyright © 2014 by William D. Parry


Ordinary developmental stuttering is best understood and treated as a specific kind of voice problem – not as a “fluency” problem or an articulation problem, but as a voice problem.

The core of stuttering is the unreadiness of the larynx to voice the vowel sound of a word or syllable.  This occurs because the larynx is neurologically prepared to participate in the exertion of physical effort (by performing effort closure as part of a Valsalva maneuver) rather than phonation.  The neurological programming for effort attaches to the vowel sound – probably because this is heart of the word or syllable and the part that has the most energy.  Consequently, the speech mechanism gets stuck on the consonant or glottal stop that precedes the vowel – repeating, prolonging, or forcing on it – resulting in the various behaviors called “stuttering.” 

Evidence that stuttering is a “voice problem” includes the following facts:

·         Many people who stutter anticipate difficulty in saying words that start with certain consonants, but 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.  Even when forcing on a consonant, the lips or tongue are in the correct position.  In each case, the real problem is the speaker’s difficulty in producing the vowel sound that follows.  In words that begin with vowels, repetition or forcing may occur on the glottal stop – a normally brief closure of the larynx to build up and release air pressure to accentuate the beginning of an initial vowel sound.

·         Stuttering usually does not occur when voicing is not required, such as when silently mouthing words or whispering.  In such instances, the speech mechanism does not have to wait for the larynx to be ready to voice the vowel sound, because phonation is not involved, and therefore the lips and tongue are free to articulate.

·         Conversely, stuttering almost never occurs while singing, because the larynx is constantly prepared to phonate the melody which is carried on the vowel sounds.  Therefore, the lips and tongue are free to articulate, because they don’t have to wait for the larynx to be ready to phonate the vowels.

How Vowel Sounds Are Voiced

In order to better understand the nature of the stutterer’s voice problem, we will first review the normal steps involved in voicing vowels. 

Located in the larynx are your vocal folds (or “vocal cords”).  Usually they are in an open position, attached at one end in V-shaped arrangement, with air flowing between them.  In order for voice to be produced, several small muscles in the larynx move the vocal folds into a closed position, across the airway.  As your out-flowing air passes between them, it causes the vocal folds to vibrate.  This vibration is called phonation.

Above the vocal folds are the vestibular folds (or “false vocal cords”).  They play a role in another function of the larynx, called effort closure.    

The first step in speaking is inhaling.  You must begin by taking in the air that will be used to create and carry the sounds of speech.  During inhalation, your vocal folds are in the open position.  The open space between the vocal folds is called the glottis.

Inhale through your nose, using your diaphragm.   The diaphragm is a thin, dome-shaped muscle that separates your chest cavity from your abdominal cavity.  As you contract your diaphragm, it flattens out, compressing the intestines in your abdominal cavity, causing the front of your abdomen to bulge out slightly.  Other muscles raise your ribcage, further enlarging your chest cavity.  Your lungs are elastic, like balloons, and expand along with the interior chest wall.  As the lungs to expand, they suck in air.  This is the air that you will use for speaking. 

Speech is done on the outward flow of air.  All you need to do to release the air is to relax the muscles that you used for inhaling.  The relaxed diaphragm will return to its dome shape, allowing the front of your abdomen to go back in.  Your ribcage will lower, your chest cavity will get smaller, and your lungs will shrink due to their elasticity, releasing a relaxed, outward flow of air. 

In Valsalva Stuttering Therapy, it is also important to intentionally relax your abdomen, all the way down to your rectal muscles, as you exhale.  The abdominal and rectal muscles are part of the Valsalva mechanism.  Relaxing them will relax the entire Valsalva mechanism and help to free your larynx to phonate.

Just prior to phonation, the brain neurologically prepares certain muscles in the larynx to bring the vocal folds gently together with an appropriate amount of tension.  This neurological programming is called prephonatory tuning.  It occurs a fraction of a second before the voice is heard. 

Although several little muscles adjust the vocal folds to the desired pitch and tension, phonation itself usually does not require much muscular effort.  What powers phonation is not muscular effort in the larynx, but rather the airflow that’s coming from the lungs, as you relax.  When the vocal folds are gently closed, the out-flowing air ripples the vocal folds, producing a buzzing sound, which is what phonation really is. 

The larynx does not produce the actual vowel sounds.  All that comes out of the larynx is a buzz.  The buzz of phonation is shaped into specific vowel sounds by changing the size and shape of your mouth cavity by putting the tongue and lips in different positions.

Nature of the Voice Problem

The behaviors called “stuttering” result from the unreadiness of your larynx to voice vowel sounds.  You should tell your listeners: “I have a voice problem.  Sometimes my larynx isn’t ready to phonate the vowel sound of a word or syllable.  Then I have to stop and get my larynx ready to voice the vowel.”  Valsalva Stuttering Therapy provides procedures for doing this.

This voice problem may be triggered and perpetuated by a variety of unhelpful beliefs, expectations, and fears which have accumulated through years of stuttering.  Typical thoughts are: “Speech is difficult”; “I always stutter in this situation, or on certain words or sounds”; and “It will be terrible if I stutter.”  Some of the triggers may be unconscious.

Based on such underlying beliefs, expectations, and fears, the person who stutters typically forms certain counter-productive intentions when approaching speaking situations.  The most common is: “It’s important that I make a good impression by trying hard not to stutter.”  Accordingly, the person who stutters forms the intention to use effort to control the outcome of his speech (e.g., making a “good impression” by not stuttering).  Ironically, by using of effort in attempting to control the outcome, the stutterer sabotages the processes that actually need to occur in order to produce speech.  This almost always increases the likelihood of stuttering.

First, this intention causes his brain’s amygdalae to go on high alert to detect upcoming words, sounds, or external cues that may be associated with memories of past stuttering.  When such a triggering stimulus is encountered, the amygdalae send out signals that initiate a fear reaction (also known as the fight-flight-freeze response) and the release of stress hormones. 

The brain then prepares the larynx to close tightly to perform effort closure as part of a Valsalva maneuver.  This maneuver is a natural bodily function designed to build up air pressure in the lungs to stiffen the trunk of the body, so as to assist in the exertion of physical effort or to ward off attacks by enemies.  During effort closure, both the vocal folds and the vestibular folds (which are located slightly higher in the larynx) tightly squeeze together to block airflow from the lungs.

Meanwhile, the abdominal muscles contract so as to push up the diaphragm and increase air pressure in the lungs.  The greater the air pressure, the more tightly the vocal folds and vestibular folds squeeze to keep the air in.  Even if the larynx does not actually close, it is not neurologically prepared to bring the vocal folds gently together for phonation of the vowel sound.  Consequently, there is a “vowel-phonation gap” in the motor program for saying the word, which the speaker may perceive as a “brick wall.”

Because the larynx is not ready to voice the vowel sound, the speaker hesitates, or his speech mechanism gets stuck on the consonant or glottal stop that precedes the vowel – repeating, prolonging, or forcing on it.  Meanwhile, the stress hormones impair the speaker’s rational thinking and create a strong urge to force out the word quickly by using physical effort.  The articulation of consonants may turn into forceful closures by the lips or tongue to build up air pressure as in a Valsalva maneuver.  The harder the speaker tries to force out the words, the tighter these closures become.  These struggles to overcome the vowel phonation gap are the behaviors called “stuttering.”

The speaker may instinctively feel that using effort is the “right” thing to do – perhaps the only thing to do.  It may even help to reduce his anxiety to some extent.  However, the use of effort continues to obstruct voicing of the vowel.  The speaker’s attempt to force out the word blocks the airflow needed to vibrate the vocal folds and to produce sound, and it further prevents programming of the larynx to phonate the vowel sound. 

This vocal core of stuttering blocks” is graphically illustrated by the following diagram (click here).

Why Redefining Stuttering as a Voice Problem Is Important

It is important, both from a conceptual and therapeutic standpoint, to let go of the mindset that stuttering is a fluency problem or an articulation problem, and to accept it as a voice problem instead. We might even give it a new name, such as “selective vowel aphonia” – referring to the occasional inability to phonate the vowel sounds of certain words in certain situations.

Viewing stuttering as a voice problem helps us to let go of the counter-productive quest for fluency. Our attention is no longer focused on the outward struggle behaviors the repetitions, prolongations, and forceful blocks. We no longer need to waste time on stuttering modification, fluency shaping, or “voluntary stuttering. Furthermore, this view of stuttering clarifies the interaction of the various psychological, neurological, and physical factors thus eliminating the stigma attached to stuttering as a sign of neurological weakness or emotional disturbance. 

Viewing stuttering as a voice problem enables us to zero in on the root of the problem and focus on ways to solve it more efficiently. Once the voice problem is fixed, the behaviors called stutteringwill resolve themselves.

Contact Information:

William D. Parry, CCC-SLP

A licensed speech-language pathologist, offering Valsalva Stuttering Therapy by video conferencing over the Internet (depending on location and subject to applicable law). 

Mail: P.O. Box 55, Merion Station, PA 19066-0055

Phone: 215-620-6792



Stuttering Therapy and Counseling:

The Valsalva-Stuttering Network:

Valsalva Stuttering Therapy is a new approach to improving fluency by controlling the physiological mechanism that may contribute to stuttering blocks. For further information on Valsalva Stuttering Therapy, visit Stuttering Therapy and Counseling at  If you are interested in therapy, send an e-mail to to inquire about a free consultation. 

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

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

National Stuttering Association

1460 Broadway, New York, NY 10036

(800) 937-8888


Updated 5/23/2020

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Last revised: 5/17/2014

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