Semester of Graduation

Spring 2020


Master of Arts (MA)


Communication Sciences and Disorders

Document Type



Purpose: The purpose of this study was to evaluate speech changes in Parkinson’s disease (PD) while reading a passage, using both local (i.e., segment level) and global (i.e., utterance level) acoustic measures.

Methods: 20 speakers participated in the study (10 PD, 10 neurologically healthy controls). The speakers were asked to read The Caterpillar passage in a conversational mode. A total of five acoustic measures were included (local: vowel duration, Euclidean distance between corner vowels and schwa; global: articulation rate, F0/intensity range). These acoustic measures were compared between two sentences located in the two positions within the paragraph, initial and final.

Results: The findings indicated (1) overall speech differences between the two groups such as increased vowel duration and reduced vowel contrast and (2) speech differences between the beginning and end of the passage such as increased articulation rate toward the end. In addition, the results revealed that unlike control speakers, speakers with PD did not show a greater F0 and intensity range in the end compared to the beginning of the passage, which points a limited capability of prosody modulations in PD and its apparent pattern toward the end of passage reading.

Discussion: Findings of this study support the notion that within- or across-task acoustic variation should be considered in speech sampling in clinical practice and research.

Committee Chair

Kim, Yunjung