The aim of this project is to evaluate articulatory characteristics in Parkinson's disease inferred from the acoustic signal. Accelerated speaking rate in PD coupled with reductions in amplitude (hypokinesia) and velocity (bradykinesia) of articulatory movements suggest increased overlap of gestures and or reductions in gesture magnitude in comparison to utterances produced at habitual rates by healthy speakers. Slowing speaking rate in PD may be associated with reductions in gesture overlap although evidence for decoupling of spatial and temporal articulatory relationships in Pd suggests that gesture magnitude may not be influenced by speaking rate as for healthy speakers. This project uses principles of gesture sliding and gesture magnitude to account for articulatory deficits as inferred from the acoustic signal F2 trajectories will be used as an acoustic representation of vowel gestures; F2 onset frequency will be used as an index of gesture overlap. There issues are relevant to the understanding of disordered speech motor control in this population and may be incorporated into a treatment.
