Basic parameters of articulatory movements and acoustics in individuals with Parkinson's disease§


  • Bridget Walsh PhD,

    Corresponding author
    1. Department of Speech, Language, and Hearing Research, Purdue University, West Lafayette, Indiana, USA
    • CCC-SLP, Purdue University, Department of Speech, Language, and Hearing Sciences, 1353 Heavilon Hall, 500 Oval Drive, West Lafayette, IN 47907-2038
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  • Anne Smith PhD

    1. Department of Speech, Language, and Hearing Research, Purdue University, West Lafayette, Indiana, USA
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  • Funding agencies: National Institute on Deafness and Other Communication Disorders, National Institutes of Health (F31DC007267-01 and R01DC00559); Indiana Lions Club (67313533762); Parkinson's Awareness Association of Central Indiana (201116).

  • Relevant conflicts of interest/financial disclosures: Nothing to report.

  • §

    Full financial disclosures and author roles may be found in the online version of this article.


It has long been recognized that lesions of the basal ganglia frequently result in dysarthria, in part because many individuals with Parkinson's disease (PD) have impaired speech. Earlier studies of speech production in PD using perceptual, acoustic, and/or kinematic analyses have yielded mixed findings about the characteristics of articulatory movements underlying hypokinetic dysarthria associated with PD: in some cases reporting reduced articulatory output, and in other instances revealing orofacial movement parameters within the normal range. The central aim of this experiment was to address these inconsistencies by providing an integrative description of basic kinematic and acoustic parameters of speech production in individuals with PD. Recordings of lip and jaw movements and acoustic data were collected in 16 individuals with PD and 16 age- and sex-matched neurologically healthy older adults. Our results revealed a downscaling of articulatory dynamics in the individuals with PD, evidenced by decreased amplitude and velocity of lower lip and jaw movements, decreased vocal intensity (dB sound pressure level [SPL]), and reduced second formant (F2) slopes. However, speech rate did not differ between groups. Our finding of an overall downscaling of speech movement and acoustic parameters in some participants with PD provides support for speech therapies directed at increasing speech effort in individuals with PD. © 2012 Movement Disorder Society