Date of Award


Document Type


Degree Name

Master of Science (MS)


Special Education and Clinical Services

First Advisor

Lori E. Lombard, Ph.D., CCC-SLP

Second Advisor

David W. Stein, Ph.D., CCC-SLP

Third Advisor

Cynthia McCormick Richburg, Ph.D., CCC-A


Consistent production of repetitive phonatory tasks requires intact fine motor control of laryngeal musculature. Repetition of glottal syllables /h^/ and /^/, the two laryngeal diadochokinetic (LDDK) tasks, isolates laryngeal functioning by eliminating oral involvement during phonation. Existing literature has identified LDDK task performance as an assessment of laryngeal function with the potential to identify the presence of neuromuscular disorders. However, current research on LDDK does not provide sufficient normative data for its use as a meaningful clinical measure. The purpose of this study was to collect and compare data for /^/ and /h^/ to determine production consistency in 47 normal participants between the ages of 60 and 90 years. Gender comparisons were also identified. Mean, standard deviation, and range were established for male and female participants 60 to 90 years of age. Results revealed no statistically significant task or gender differences.