title: Voice Signals Produced With Jitter Through a Stochastic One-mass Mechanical Model.
abstract: BACKGROUND
  The quasiperiodic oscillation of the vocal folds causes perturbations in the length of the glottal cycles, which are known as jitter. The observation of the glottal cycles variations suggests that jitter is a random phenomenon described by random deviations of the glottal cycle lengths in relation to a corresponding mean value and, in general, its values are expressed as a percentage of the duration of the glottal pulse.
  
  
  OBJECTIVE
  The objective of this paper is the construction of a stochastic model for jitter using a one-mass mechanical model of the vocal folds, which assumes complete right-left symmetry of the vocal folds, and which considers motions of the vocal folds only in the horizontal direction.
  
  
  METHODS
  The jitter has been the subject for researchers due to its important applications such as the identification of pathological voices (nodules in the vocal folds, paralysis of the vocal folds, or even, the vocal aging, among others). Large values for jitter variations can indicate a pathological characteristic of the voice.
  
  
  METHODS
  The corresponding stiffness of each vocal fold is considered as a stochastic process, and its modeling is proposed.
  
  
  RESULTS
  The probability density function of the fundamental frequency related to the voice signals produced are constructed and compared for different levels of jitter. Some samples of synthesized voices in these cases are obtained.
  
  
  CONCLUSIONS
  It is showed that jitter could be obtained using the model proposed. The Praat software was also used to verify the measures of jitter in the synthesized voice signals.
authors.affiliation: Universidade Federal Fluminense, Applied Mathematics Departament and Graduate Program in Telecommunications Engineering, Rua Mário Santos Braga, S/N, Centro, Niteroi, RJ, CEP: 24020-140, Brazil. Electronic address: ecataldo@im.uff.br.
authors.forename: Edson
authors.initials: E
authors.lastname: Cataldo
authors.affiliation: Université Paris-Est, Laboratoire Modelisation et Simulation Multi Echelle, MSME UMR 8208 CNRS, 5 Bd Descartes, 77454 Marne-La-Vallée, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Soize
mesh_terms: D001696:Biomechanical Phenomena; D003198:Computer Simulation; D004548:Elasticity; D006801:Humans; D008962:Models, Theoretical; D017711:Nonlinear Dynamics; D010699:Phonation; D011312:Pressure; D012984:Software; D013269:Stochastic Processes; D014827:Vocal Cords / Q000033:anatomy & histology / Q000502:physiology*; D014833:Voice Quality
keywords: Jitter; Mathematical models; Mechanical models; Stochastic modeling; Voice production