Understanding & Controlling Stuttering

Understanding & Controlling Stuttering

A Comprehensive New Approach Based on the Valsalva Hypothesis

The Ultimate Expanded Fourth Edition (2021)

Front cover
By William D. Parry, J.D
., M.A., CCC-SLP

Trade paperback, 354 pages, 6 x9 inches, perfect

bound, ISBN: 978-1-7379555-0-4


Are you frustrated and puzzled about stuttering blocks?

If so, here is a book, written in clear, every-day language, that fits together the pieces of the stuttering puzzle more completely than ever before. The key to its approach is the Valsalva Hypothesis – which describes the psychological, neurological, and physiological factors that interfere with a person’s natural speaking ability when triggered by the brain’s amygdala. It explains how these factors cause stuttering blocks by suppressing phonation of a word’s main vowel sound and replacing it with an impulse to exert force on the preceding consonant or glottal stop by means of a Valsalva maneuver. The blocks are then reinforced and perpetuated through a "Valsalva-Stuttering Cycle."

This Ultimate Expanded Fourth Edition sheds new light on virtually every aspect of stuttering – its causes, its variability, its paradoxes, its many forms of treatment, and the importance of accepting stuttering rather than trying to be “fluent.”  Finally, it provides detailed instructions for exercises that were developed through actual clinical experience and experimentation involving more than 200 participants in Valsalva Stuttering Therapy from all over the world.

This Fourth edition is based on an enhanced Valsalva Hypothesis that is more comprehensive than in previous editions. It features new and improved exercises and strategies designed to relax the body’s Valsalva mechanism, promote vowel phonation, dissolve stuttering blocks, and improve attitudes about speech, thereby allowing you to speak in an easier, less effortful, and natural-sounding way.

What others have said about a previous edition . . .

"Lucid, easy-to-read . . . . You learn to see your stuttering in an entirely new light. . . . Bill has identified and demystified one of the key elements of the [stuttering] system - the speech block - and he does it in a way that makes perfect sense. His book ... is essential reading for anyone trying to make sense of his or her own stuttering. It's also a must for the speech pathologist looking for a keener understanding of the hidden dynamics behind the stuttering block."

John C. Harrison - Review in Letting Go, National Stuttering Project

"A well-researched book which benefits from the author's personal experience of stammering."

Dr. Trudy Stewart - Review in Speaking Out, Association for Stammerers (England)

"[The Valsalva Hypothesis] is of potentially significant scientific value in explaining the nature of stuttering behavior. . . . "

J. David Williams, Ph.D., Northern Illinois University

William D. Parry, CCC-SLP, is a speech-language pathologist who previously overcame his own stuttering through self-therapy based on his Valsalva Hypothesis. This helped  him become a successful trial lawyer. He founded and led the Philadelphia Area Chapter of the National Stuttering Association, served on the NSA’s board of directors, and has presented workshops throughout the U.S. and internationally.

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How to order . . .

The Ultimate Expanded Fourth Edition of Understanding & Controlling Stuttering is now available at Amazon.com and the National Stuttering Association website, and as an ebook in PDF.



Or buy it from the

National Stuttering Association

and help support the NSA.


Updated: November 4, 2021

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