Control of Transglottal Airflow in Vowels and Connected Speech of Speakers with Parkinson's Disease

Abstract

This study sought to compare the transglottal airflow of speakers with Parkinson's disease (PD) to that of healthy older adults (HOA). Researchers examined both amount of expired transglottal airflow and consistency of transglottal airflow. A database of existing recordings was utilized to assess the transglottal airflow of 18 individuals with PD and 11 HOAs. An additional 11 HOAs were recruited and tested using the Phonatory Aerodynamic System. Participants completed three trials of two speaking tasks designed to assess vowel productions and sentence productions. Data generated from the two tasks was used to compare airflow between groups as measured in mL/second. Researchers examined the means of airflow across sentence trials and vowel trials, as well as the standard deviations of airflow across sentence trials, across vowel trials, and within vowel trials. Results of two independent samples t-tests indicated that the PD group produced a statistically significant higher mean airflow in sentences (p<.001) and vowels (p=.01). Results of a MANOVA indicated that the PD group also had statistically significant higher standard deviations of airflow across sentence tasks (p=.025), across vowel tasks (p=.035), and within vowel tasks (p=.028). Such findings suggest that PD interferes with the regulation of transglottal airflow during speech.