AN EVALUATION OF VOCAL ANALYSIS RESEARCH RELATING TO PARKINSON'S DISEASE

Abstract

Parkinson's Disease (PD) is a progressive neurodegenerative disease affecting almost 10 million individuals globally. It is characterized by tremors, slowness of movement, and vocal dysfunction. Voice dysfunction is one of the earliest indicators of PD and includes breathiness, roughness, reduced loudness, etc. Because most research relates to vocal fold pathology, our understanding of the brain pathology is not well understood prompting insight from animal models such as finch and rodents. These studies have shed light on how the accumulation of Lewy bodies (the aggregated form of the alpha-synuclein protein), and neurites can be key to the progression of symptoms and how it might relate to the vocal measures used in humans. Here, we review current research on the various acoustic measures utilized for PD, evaluate the limitations and strengths of the numerous measures, and provide studies which utilize the same measures. There is a multitude of both speech and voice measures that have been investigated for PD. Various studies demonstrate the potential of these measures in differentiating between those with PD and healthy controls. Yet, there are limitations to current studies including small sample size, methodological inconsistencies, and most importantly, the need for more shared measures. Ultimately, there is a need for further exploration across larger and more diverse subject populations in the future as it will expand our understanding of the disease's pathology, leading to breakthroughs in both PD diagnosis and treatment.