ISCA Archive MAVEBA 2001
ISCA Archive MAVEBA 2001

Physical models of the vocal folds including pathologies

Xavier Pelorson, Mico Hirschberg

The production of voiced sounds is now well understood as being the result of a spectacular interaction between an elastic structure, the vocal folds, and an airflow coming from the lungs. Under certain circumstances an instability, a flutter, can indeed occur and can lead to a self-sustained oscillation of the vocal folds. One of the goal of physical modelling is, first of all, to try to understand what are the basic mechanical and fluid mechanical phenomenon involved during phonation. When studying pathologies such as vocal folds paralysis or (partial-) laryngectomy, physical modelling can gain sometimes an extra interest as a valuable tool not only for diagnostic or analysis purposes (e.g. Herzel, 1996) but also for predicting the consequences of surgery events or for the design of voice prosthesis (Lous et al., 1998). In this presentation, a review of existing physical models of the vocal folds, and their relevance for the purpose of voice pathology studies, will be presented. In particular it will be shown that one has to face the problem dealing with the trade-off that has to be done between the complexity of the studied phenomenon (especially when pathologies are present) and the necessary assumptions or simplifications of the models. Lastly, it will be shown that the real challenge of physical models is not to increase the number of parameters but to decrease it to a physiologically plausible amount. In depth physical studies of critical events such as the onset of voicing, the mechanical contact of the vocal folds or the physical boundary conditions can help in that purpose as it will be demonstrated.

s: Herzel H. (1996) "Possible mechanisms of vocal instabilities" in Vocal Folds Physiology, P.J. Davis and N.H. Fletcher Eds, Singular Publishing Group, San Diego. 63-75. N.J.C. Lous, G.C.J. Hofmans, R.N.J. Veldhuis, A. Hirschberg (1998) "A Symmetrical Two- Mass Vocal-Fold Model Coupled to Vocal Tract and Trachea, with Application to Prosthesis Design", Acta Acustica, 84, 1135-1150.

Cite as: Pelorson, X., Hirschberg, M. (2001) Physical models of the vocal folds including pathologies. Proc. Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA 2001), 1

  author={Xavier Pelorson and Mico Hirschberg},
  title={{Physical models of the vocal folds including pathologies}},
  booktitle={Proc. Models and Analysis of Vocal Emissions for Biomedical Applications (MAVEBA 2001)},