Reference: Advance for Speech-Language Pathologists and Audiologists Sept. 19, 2011
Stuttering affects 3 million Americans and four times as many men as women. Approximately 5 percent of young children go through a period of stuttering that lasts six months or more. The majority recover by late childhood, leaving only about 1 percent with a long-term stutter.
Adolescent and adult stutterers have a different awareness of the disorder as a result of a lifetime of disfluency. Of particular interest to Courtney Byrd, PhD, assistant professor in the Department of Communication Sciences and Disorders, College of Communication, at the University of Texas in Austin, is seeing if the unique behaviors she has identified in young children at the onset of stuttering persist into adulthood.
Learning how stutterers select and organize the sounds they use to make words helps researchers identify the obstacles that result in stuttering and develop therapies to overcome them. In the Developmental Stuttering Lab, which she established at the college five years ago, Dr. Byrd and her team of graduate and undergraduate students evaluate how typically developing presechoolers acquire language and learn how to put sounds together fluently. These evaluations range from observing parents laying and talking with their children, to analyzing characteristics of disfluent speech, to measuring speech fluency as a child describes a picture, to asking children to identify words based on partial sounds. The data are used to create benchmarks against which to compare children who stutter and pinpoint the breakdown in fluency.
Children who stutter take longer to select sounds because they are not efficiently organized, which means stuttering is not strictly motoric, or a speech behavior, but there is a linguistic component as well, Dr. Byrd’s research suggests.
Up until about age 2-and-a-half, she said, children’s speech consists of a constellation of unrelated but familiar words, such a mommy, daddy, baby, milk, and book. During a vocabulary growth spurt by age 3, they start to organize language into global syllable shapes, or neighborhoods, of words that differ by only one individual sound segment, such as back, bath, bag, bad, and bat.
“This global syllable shape selection strategy enables 3-year-olds to efficiently organize and access their limited vocabulary,” said Dr. Byrd. “However, by age 5 an expanded vocabulary compounded by faster utterances and longer, more complex phrases makes it inefficient for typically developing children to rely on this strategy. In fact, it inhibits their ability to produce speech fluently.”
In contrast to typically developing children and adults, she said, “‘my research has shown both children and adults who stutter continue to rely on the global syllable shape organization system, which is inefficient and slows their ability to access the individual sound segments that represent the words they’re trying to say. The outcome is what we perceive as stuttered speech.”
She hopes her research will lead to the identification of key etiological factors that could be used to transform treatment. “But stuttering is a complex disorder,” she said. “It waxes and wanes, and its origins are unclear.”
“While we work with clients to improve their fluency through speech therapy, we also give them practical coping mechanisms. For example, the simple act of self-disclosure can ease the burden and make the stutterer and others feel comfortable,” Dr. Byrd stated.