It is well documented that changes in speech occur with age and can be augmented by the presence of neuropathology (Little et. al, 2009; Ramig & Ringel, 1983; Sadagopan & Smith, 2013). Parkinson's disease (PD) is a progressive, neurodegenerative disorder that can have a profound effect on speech and its subsystems. Advances in technology and the use of acoustic applications have made it possible to objectively measure PD speech, and the current literature reports success in accurately differentiating PD speakers from healthy speakers. The present study was conducted with two goals in mind. First, to determine whether acoustic variables can be used to differentiate PD speakers from healthy speakers during times before the clinical diagnosis of PD. Second, to determine the usefulness of acoustic variables for monitoring the disease progression of PD. To achieve this, recordings spanning two to seven decades were obtained for 10 PD speakers and 9 control speakers. Recordings were edited for target speaker and assigned to a speaker group: PD Pre-Dx, PD Post-Dx, or Control. Values for voice and articulation measures were obtained from the recordings, and ANOVA and ANCOVA analyses were completed using MATLAB. A second ANOVA and ANCOVA analysis was performed on a combined PD speaker group and the Control group. Several acoustic measures demonstrated PD Pre-Dx group mean values significantly less than Control group mean values, making them a potential tool for early PD detection. Other acoustic measures demonstrated trends that may show potential in future research for use in PD progression monitoring. Limitations of study and suggestions for future research are discussed
