title: [Reproducibility and reliability of phonovibrograms. Quantification of healthy vocal fold vibrations].
abstract: BACKGROUND
  Phonovibrography is capable of visualizing vocal fold vibrations in a static two-dimensional image, the so-called phonovibrogram (PVG). It allows quantification of the entire vocal fold vibration patterns. In this study we investigated the accuracy and reproducibility of PVG measures by analyzing high-speed laryngoscopy videos of healthy vocal fold vibrations.
  
  
  METHODS
  High-speed laryngoscopy videos of 12 female speech therapists and 12 vocalists from the Regensburg Cathedral choir were analyzed. For evaluation purposes, PVG analysis was performed for two different sections of each video.
  
  
  RESULTS
  The mean difference between the high-speed sections was 1.6 degrees +/-0.5 degrees for the female and 2.3 degrees +/-0.6 degrees for the male subjects. Within the sections, the mean variance of the PVG parameters was 3.5 degrees +/-0.7 degrees (therapists) and 3.7 degrees +/-1.0 degrees (vocalists). Likewise, a high left/right accordance of the PVG parameters, 5.3 degrees +/-0.5 degrees for therapists and 5.9 degrees +/-1.9 degrees for vocalists, was obtained.
  
  
  CONCLUSIONS
  Vibrational patterns of normal vocal fold vibrations were very precisely quantified by the introduced PVG parameters. The high accuracy and reproducibility of PVG analysis provides a basis for prospective clinical trials dealing with precise characterization of pathological vibration patterns.
authors.affiliation: Abteilung für Phoniatrie und Pädaudiologie, Universitätsklinikum Erlangen, Bohlenplatz 21, 91054, Erlangen.
authors.forename: J
authors.initials: J
authors.lastname: Havla
authors.forename: M
authors.initials: M
authors.lastname: Döllinger
authors.forename: U
authors.initials: U
authors.lastname: Eysholdt
authors.forename: J
authors.initials: J
authors.lastname: Lohscheller
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D007828:Laryngoscopy / Q000379:methods*; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013068:Speech Production Measurement / Q000379:methods*; D014732:Vibration; D014741:Video Recording / Q000379:methods; D014827:Vocal Cords / Q000033:anatomy & histology / Q000502:physiology*; D055815:Young Adult