title: Prosodic analysis of neutral, stress-modified and rhymed speech in patients with Parkinson's disease.
abstract: OBJECTIVE
  Hypokinetic dysarthria (HD) is a frequent speech disorder associated with idiopathic Parkinson's disease (PD). It affects all dimensions of speech production. One of the most common features of HD is dysprosody that is characterized by alterations of rhythm and speech rate, flat speech melody, and impairment of speech intensity control. Dysprosody has a detrimental impact on speech naturalness and intelligibility.
  
  
  METHODS
  This paper deals with quantitative prosodic analysis of neutral, stress-modified and rhymed speech in patients with PD. The analysis of prosody is based on quantification of monopitch, monoloudness, and speech rate abnormalities. Experimental dataset consists of 98 patients with PD and 51 healthy speakers. For the purpose of HD identification, sequential floating feature selection algorithm and random forests classifier is used. In this paper, we also introduce a concept of permutation test applied in the field of acoustic analysis of dysarthric speech.
  
  
  RESULTS
  Prosodic features obtained from stress-modified reading task provided higher classification accuracies compared to the ones extracted from reading task with neutral emotion demonstrating the importance of stress in speech prosody. Features calculated from poem recitation task outperformed both reading tasks in the case of gender-undifferentiated analysis showing that rhythmical demands can in general lead to more precise identification of HD. Additionally, some gender-related patterns of dysprosody has been observed.
  
  
  CONCLUSIONS
  This paper confirms reduced variation of fundamental frequency in PD patients with HD. Interestingly, increased variability of speech intensity compared to healthy speakers has been detected. Regarding speech rate disturbances, our results does not report any particular pattern. We conclude further development of prosodic features quantifying the relationship between monopitch, monoloudness and speech rate disruptions in HD can have a great potential in future PD analysis.
authors.affiliation: Department of Telecommunications, Brno University of Technology, Technicka 10, 61600 Brno, Czech Republic.
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Galaz
authors.affiliation: Department of Telecommunications, Brno University of Technology, Technicka 10, 61600 Brno, Czech Republic.
authors.forename: Jiri
authors.initials: J
authors.lastname: Mekyska
authors.affiliation: Department of Telecommunications, Brno University of Technology, Technicka 10, 61600 Brno, Czech Republic.
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Mzourek
authors.affiliation: Department of Telecommunications, Brno University of Technology, Technicka 10, 61600 Brno, Czech Republic.
authors.forename: Zdenek
authors.initials: Z
authors.lastname: Smekal
authors.affiliation: First Department of Neurology, St. Anne's University Hospital, Pekarska 53, 65691 Brno, Czech Republic; Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University, Komenskeho nam. 2, 60200 Brno, Czech Republic. Electronic address: irena.rektorova@fnusa.cz.
authors.forename: Irena
authors.initials: I
authors.lastname: Rektorova
authors.affiliation: First Department of Neurology, St. Anne's University Hospital, Pekarska 53, 65691 Brno, Czech Republic; Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University, Komenskeho nam. 2, 60200 Brno, Czech Republic.
authors.forename: Ilona
authors.initials: I
authors.lastname: Eliasova
authors.affiliation: Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University, Komenskeho nam. 2, 60200 Brno, Czech Republic; Department of Neurology, Faculty Hospital and Masaryk University, Jihlavska 20, 63900 Brno, Czech Republic.
authors.forename: Milena
authors.initials: M
authors.lastname: Kostalova
authors.affiliation: First Department of Neurology, St. Anne's University Hospital, Pekarska 53, 65691 Brno, Czech Republic; Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University, Komenskeho nam. 2, 60200 Brno, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Mrackova
authors.affiliation: Applied Neuroscience Research Group, Central European Institute of Technology, Masaryk University, Komenskeho nam. 2, 60200 Brno, Czech Republic.
authors.forename: Dagmar
authors.initials: D
authors.lastname: Berankova
mesh_terms: D000465:Algorithms; D016022:Case-Control Studies; D006801:Humans; D010300:Parkinson Disease / Q000503:physiopathology*; D013064:Speech Disorders / Q000503:physiopathology*; D013312:Stress, Physiological
keywords: Dysprosody; Feature selection; Hypokinetic dysarthria; Parkinson's disease; Random forests