Semester of Graduation

Fall 2018


Master of Arts (MA)


Communication Disorders

Document Type




Purpose: The aim of this study is to detect and track speech changes using acoustic and perceptual measures in an individual (a local newscaster) with amyotrophic lateral sclerosis (ALS) using data from before her diagnosis, around the time of her diagnosis, and after her diagnosis.

Methods: Six time points, ranging from 37 months around her diagnosis, were analyzed from one speaker with ALS. Three acoustic parameters were measured: articulation rate, acoustic vowel space, and the slope of the second formant. Additionally, two experts with more than 10 years of experience perceptually analyzed the speech samples on 17 characteristics using a 7-point scale.

Results: The findings of this study revealed a decline in most parameters, both acoustic and perceptual, in the last time point, as expected. Additionally, a gradual increase in articulation rate, acoustic vowel space, and the number of syllables per utterance is observed before a decline after time point 4.

Discussion: The gradual increase in some parameters before a decline may reflect the speaker’s compensatory strategies. After time point 4, it is suspected the speaker could no longer compensate, and thus a decline is observed. Additionally, both perceptual and acoustic measures indicate speech changes over time; however, acoustic measures (i.e. articulation rate) appear to provide objective data to support subtle, perceptual changes between time points.



Committee Chair

Kim, Yunjung