The long-range goal of this research is to develop objective measures for evaluating the type and severity of speech production disorders, different dysarthrias, associated with various neurological diseases. Measures made from spectrographic analyses of the acoustic waveform of dysarthric subjects' speech will be evaluated to determine which measures: a) differentiate between the speech of Parkinson patients and normal adults of the same age and sex, b) differentiate between speech symptoms occurring in Parkinson patients in two different states; moderate to severe rigidity with bradykinesia and drug induced dyskinesia, c) differentiate between speech symptoms occurring in Parkinson patients receiving different drugs; L-Dopa and Bromocriptine, $ d) differentiate between the speech characteristics of patients with different neurologic diseases; Parkinson's disease, Huntington's chorea, amyotrophic lateral sclerosis, and cerebellar dysfunction, e) correlate with perceptual judgments of the degree of speech production impairment, f) have adequate within subject test-retest reliability, and g) can be measured from spectrographic analyses of the same speech recording with minimal error.