Date of Award

Spring 5-2016

Document Type


Degree Name

Master of Science (MS)


Communication Disorders, Special Education & Disability Services

First Advisor

Lori Lombard, Ph.D.

Second Advisor

David W. Stein, Ph.D.

Third Advisor

Cynthia M. Richburg, Ph.D.


Laryngeal Diadochokinesis (L-DDK) is a task used to assess fine motor control of the vocal mechanism. L-DDK is a task in which an individual repetitively produces the syllables /ʌ/ and /hʌ/ as rapidly and consistently as possible for a duration of seven seconds. L-DDK is useful because it provides information about rate, strength, and consistency of neuromotor control, allowing clinicians to determine if further testing is required. Current literature regarding L-DDK does not provide normative data for strength of laryngeal functioning based on L-DDK measures in the adult population. Development of normative data would assist speech-language pathologists in assessment of laryngeal strength and motor control of the larynx, as well as help to identify patients presenting with neurologic diseases such as ALS and Parkinson’s, among others. This study serves to provide normative data for L-DDK measures of strength for the adult population between 40 and 59 years of age.