Date of Award

Spring 5-2016

Document Type


Degree Name

Master of Science (MS)


Communication Disorders, Special Education & Disability Services

First Advisor

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

Second Advisor

Jill Brady, Ph.D., CCC-SLP

Third Advisor

Lisa Hammett Price, Ph.D., CCC-SLP


Laryngeal Diadochokinesis (L-DDK) is widely used by speech-language pathologists as a method of assessing laryngeal function during evaluations. Although this method has proven to be a beneficial screening approach, a lack of normative data weakens the use of L-DDK as a clinical tool. This study aims to strengthen research on L-DDK by providing normative data on L-DDK strength measurements in the young adult population (age 20-39 years old). These measurements were collected from 99 participants (55 females and 44 males). Participants were instructed to complete two L-DDK tasks, the rapid repetition of /ʌ/ and /hʌ/, for seven seconds each across three trials. The strength of production of both L-DDK tasks was analyzed. Normative data including minimum and maximum L-DDK strength values, mean, and standard deviation were calculated. The results indicated a statistically significant difference in productions of /ʌ/ and /hʌ/. However, there was no significant difference between males and females.