title: Automated measurement of vocal fold vibratory asymmetry from high-speed videoendoscopy recordings.
abstract: OBJECTIVE
  In prior work, a manually derived measure of vocal fold vibratory phase asymmetry correlated to varying degrees with visual judgments made from laryngeal high-speed videoendoscopy (HSV) recordings. This investigation extended this work by establishing an automated HSV-based framework to quantify 3 categories of vocal fold vibratory asymmetry.
  
  
  METHODS
  HSV-based analysis provided for cycle-to-cycle estimates of left-right phase asymmetry, left-right amplitude asymmetry, and axis shift during glottal closure for 52 speakers with no vocal pathology producing comfortable and pressed phonation. An initial cross-validation of the automated left-right phase asymmetry measure was performed by correlating the measure with other objective and subjective assessments of phase asymmetry.
  
  
  RESULTS
  Vocal fold vibratory asymmetry was exhibited to a similar extent in both comfortable and pressed phonations. The automated measure of left-right phase asymmetry strongly correlated with manually derived measures and moderately correlated with visual-perceptual ratings. Correlations with the visual-perceptual ratings remained relatively consistent as the automated measure was derived from kymograms taken at different glottal locations.
  
  
  CONCLUSIONS
  An automated HSV-based framework for the quantification of vocal fold vibratory asymmetry was developed and initially validated. This framework serves as a platform for investigating relationships between vocal fold tissue motion and acoustic measures of voice function.
authors.affiliation: Massachusetts General Hospital, Center for Laryngeal Surgery and Voice Rehabilitation, 1 Bowdoin Square, 11th Floor, Boston, MA 02114, USA. daryush.mehta@alum.mit.edu
authors.forename: Daryush D
authors.initials: DD
authors.lastname: Mehta
authors.forename: Dimitar D
authors.initials: DD
authors.lastname: Deliyski
authors.forename: Thomas F
authors.initials: TF
authors.lastname: Quatieri
authors.forename: Robert E
authors.initials: RE
authors.lastname: Hillman
mesh_terms: D000465:Algorithms; D004724:Endoscopy / Q000379:methods* / Q000592:standards; D006801:Humans; D008954:Models, Biological; D015203:Reproducibility of Results; D013061:Speech Acoustics; D014732:Vibration; D014743:Videotape Recording / Q000379:methods* / Q000592:standards; D014827:Vocal Cords / Q000502:physiology*; D014831:Voice / Q000502:physiology*