title: Comparative analysis of vocal fold vibration using high-speed videoendoscopy and digital kymography.
abstract: OBJECTIVE
  To compare high-speed videoendoscopy (HSV) and digital kymography (DKG) in the vocal fold vibration analysis of normophonic women with no vocal fold abnormalities.
  
  
  METHODS
  Prospective study comparing quantitative parameters extracted by HSV and DKG.
  
  
  METHODS
  Eighteen normophonic women whose age ranged from 18 to 45 years participated in the study. The procedures comprised HSV and DKG of the medial line of the vocal folds. The parameters evaluated were fundamental frequency (F0), open quotient (OQ), and duration of vibration cycle phases (open phase, closed phase, opening phase, and closing phase).
  
  
  RESULTS
  The F0 results of HSV and DKG were similar. However, significant differences were found in both duration of vibration cycle phases and OQ, indicating a longer open phase in the vocal fold vibration when this phase was measured by HSV.
  
  
  CONCLUSIONS
  The results emphasize the need to set up different normative threshold values for both HSV and DKG.
authors.affiliation: Bioengineering Graduate Program EESC/FMRP/IQSC, University of São Paulo, Sao Carlos, São Paulo, Brazil. Electronic address: paulabaravieira@usp.br.
authors.forename: Paula Belini
authors.initials: PB
authors.lastname: Baravieira
authors.affiliation: Department of Speech-Language Pathology and Audiology, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil.
authors.forename: Alcione Ghedini
authors.initials: AG
authors.lastname: Brasolotto
authors.affiliation: Department of Otorhinolaryngology, University of São Paulo, School of Medicine, São Paulo, São Paulo, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Hachiya
authors.affiliation: Department of Otorhinolaryngology, University of São Paulo, School of Medicine, São Paulo, São Paulo, Brazil.
authors.forename: Marystella Tomoe
authors.initials: MT
authors.lastname: Takahashi-Ramos
authors.affiliation: Department of Otorhinolaryngology, University of São Paulo, School of Medicine, São Paulo, São Paulo, Brazil.
authors.forename: Domingos Hiroshi
authors.initials: DH
authors.lastname: Tsuji
authors.affiliation: Bioengineering Graduate Program EESC/FMRP/IQSC, University of São Paulo, Sao Carlos, São Paulo, Brazil.
authors.forename: Arlindo Neto
authors.initials: AN
authors.lastname: Montagnoli
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D007734:Kymography / Q000379:methods*; D007828:Laryngoscopy / Q000379:methods*; D008875:Middle Aged; D010699:Phonation; D011446:Prospective Studies; D015203:Reproducibility of Results; D014732:Vibration; D014741:Video Recording; D014827:Vocal Cords / Q000502:physiology*; D055815:Young Adult
keywords: High-speed videoendoscopy; Kymography; Voice analysis