title: High-speed kymography identifies the immediate effects of voiced vibration in healthy vocal folds.
abstract: BACKGROUND
  The effects of voiced vibration technique can be assessed by laryngeal imaging. Kymographic images derived from high-speed videoendoscopy allow actual visualization of vocal folds vibration.
  
  
  OBJECTIVE
  The aim of this study is to identify the immediate effects of the voiced vibration technique in healthy vocal folds using high-speed digital laryngeal imaging.
  
  
  METHODS
  Samples were obtained from 15 healthy subjects with no history of voice disorders (6 men and 9 women aged 21 to 43 years). High-speed videoendoscopy recordings were performed before and after the voiced vibration technique. Kymographic images were obtained using high-speed videoendoscopy. The vocal folds were examined in their open and closed positions and the characteristics of the opening and closing phases were determined. A customize computational routine was used quantify these parameters. The closing, opening, and speed quotients were also calculated.
  
  
  RESULTS
  In this study, women displayed statistically significant differences in opened phase (P = 0.05*), closed phase (P = 0.046*), and closing phase (P = 0.026*) phase characteristics. Men displayed the highest difference rate in opening time characteristics (P = 0.06). The closing and opening quotients for the female group showed significant differences (P = 0.029* and P = 0.049*, respectively). The speed quotient exhibited statistically significant differences in the male group (P = 0.048*).
  
  
  CONCLUSIONS
  The kymographic images indicated that the immediate effect of the voiced vibration technique was smooth contact in healthy vocal fold vibration.
authors.affiliation: Master in Bio-Engineering. Doctorate. Post Graduation in Bio-Engineering - University of São Paulo - São Carlos.
authors.forename: Regina Aparecida
authors.initials: RA
authors.lastname: Pimenta
authors.affiliation: Doctor in Sciences. Post-Doctorate. Department of Otolaryngology, School of Medicine, University of São Paulo.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Dájer
authors.affiliation: Doctor in Sciences. Department of Otolaryngology, School of Medicine, University of São Paulo.
authors.forename: Adriana
authors.initials: A
authors.lastname: Hachiya
authors.affiliation: Master in Sciences of Otolaryngology. Doctorate. Department of Otolaryngology, School of Medicine, University of São Paulo.
authors.forename: Gislaine Ferro
authors.initials: GF
authors.lastname: Cordeiro
authors.affiliation: Professor in the Department of Otolaryngology, School of Medicine, University of São Paulo.
authors.forename: Domingos Hiroshi
authors.initials: DH
authors.lastname: Tsuji
authors.affiliation: Doctor in Sciences. Professor in the Department of Electric Engineering of University Federal of São Carlos.
authors.forename: Arlindo Neto
authors.initials: AN
authors.lastname: Montagnoli
keywords: High-speed digital imaging; Kymography; Voice; Voiced vibration