title: Vortical flow field during phonation in an excised canine larynx model.
abstract: OBJECTIVE
  To more fully understand the mechanisms of vocal fold vibration and sound production, we studied the velocity flow fields above the folds. Such velocity fields during phonation have not been reported in the literature.
  
  
  METHODS
  Using the particle image velocimetry method for 3 excised canine larynges, we obtained the velocity fields in the mid-membranous coronal plane during different phases of phonation. The velocity field was determined synchronously with the vocal fold motion recorded by high-speed videography.
  
  
  RESULTS
  The results show that vortices occur immediately above the vocal folds and that the location and shape of the vortices depend on the phase of the phonation cycle. Consistent vortical structures found included starting vortices, Kelvin-Helmholtz vortices, entrainment vortices, and vortices directly above the folds during the divergent glottal stage.
  
  
  CONCLUSIONS
  These vortical structures were consistently found during specific phases of the glottal cycle for 3 canine larynges that significantly varied in size. This consistent behavior suggests that the vortices may be important for both vibration and sound production; however, further study is needed to prove this. The clinical significance of these vortices is discussed.
authors.affiliation: Dept of Otolaryngology-Head and Neck Surgery, University of Cincinnati Medical Center, 231 Albert B. Sabin Way, ML #0528, Cincinnati, OH 45267, USA.
authors.forename: Sid
authors.initials: S
authors.lastname: Khosla
authors.forename: Shanmugam
authors.initials: S
authors.lastname: Muruguppan
authors.forename: Ephraim
authors.initials: E
authors.lastname: Gutmark
authors.forename: Ronald
authors.initials: R
authors.lastname: Scherer
mesh_terms: D000162:Acoustics; D000818:Animals; D004285:Dogs; D007830:Larynx / Q000502:physiology*; D007834:Lasers; D023421:Models, Animal; D010699:Phonation / Q000502:physiology*; D010781:Photography; D012815:Signal Processing, Computer-Assisted