Acoustic analysis of parkinsonian speech I: speech characteristics and L-Dopa therapy.

This paper reviews the literature pertaining to Parkinson's disease (PD) and the speech dysfunction typically associated with PD, including the effects on respiration, phonation, articulation, resonance, and prosody. The effect of treatment with the drug L-Dopa is also examined, along with the effect of L-Dopa treatment on Parkinsonian speech. This paper is the first of a two-part series. Part two examines the literature pertaining to the fluctuations that can occur during treatment with L-Dopa, the speech changes associated with these fluctuations, and methodological issues affecting the examination of fluctuations and PD speech.