Department of Special Education and Communication Disorders


Date of this Version



Published in Journal of Communication Disorders 43:1 (2010), pp. 6-20; doi: 10.1016/j.jcomdis.2009.07.003 Copyright © 2009 Elsevier Inc. Used by permission.


The goal of this study was to investigate the deterioration of lip and jaw movements during speech longitudinally in three individuals diagnosed with bulbar amyotrophic lateral sclerosis (ALS). The study was motivated by the need to understand the relationship between physiologic changes in speech movements and clinical measures of speech performance such as speaking rate and speech intelligibility. Movements of the lip and jaw were quantified with respect to their size speed, and duration. The data revealed several changes in lip and jaw movement that coincided with ALS progression. In two out of three speakers, the changes in measures of path distance and speed anticipated the drop in speech intelligibility by approximately 3 months. With disease progression, increases in movement duration coincided with declines in speech intelligibility. Overall, the movement measures appeared to be sensitive to disease progression in ALS.