Speech is a complex motor behavior often disrupted by neurologic dysfunction. Parkinson's disease (PD) is one of the most prominent neurological disorders associated with speech disturbances. L-dopa continues to be the cornerstone of medical treatment for the motor symptoms and typically produces some improvement of speech symptoms. As the disease progresses, medical management becomes increasingly difficult and is associated with disabling side effects. Recently, deep brain stimulation (DBS) has been shown to be an effective adjunct therapy for control of the motor symptoms in select patients with advanced disease. The clinical effects of L-dopa and DBS on speech have not been consistent, and some studies report a substantial worsening of speech following these procedures. Many of the difficulties in evaluating speech arise from the subjective nature of evaluation. Even standardized protocols administered by trained professionals demonstrate significant inter-rater variability. We propose to develop a cost effective, portable, stand-alone technology package to analyze multiple components of recorded speech. We will study the applied technology in PD patients and analyze the effects of L-dopa and DBS on objective measures of speech. We will also expand our speech assessment technologies by adding new analytical tools based on sensitive, non-linear dynamic algorithms.