title: Quantitative high-speed laryngoscopic analysis of vocal fold vibration in fatigued voice of young karaoke singers.
abstract: OBJECTIVE
  The present study aimed to determine whether there were physiological differences in the vocal fold vibration between nonfatigued and fatigued voices using high-speed laryngoscopic imaging and quantitative analysis.
  
  
  METHODS
  Twenty participants aged from 18 to 23 years (mean, 21.2 years; standard deviation, 1.3 years) with normal voice were recruited to participate in an extended singing task. Vocal fatigue was induced using a singing task. High-speed laryngoscopic image recordings of /i/ phonation were taken before and after the singing task. The laryngoscopic images were semiautomatically analyzed with the quantitative high-speed video processing program to extract indices related to the anteroposterior dimension (length), transverse dimension (width), and the speed of opening and closing.
  
  
  RESULTS
  Significant reduction in the glottal length-to-width ratio index was found after vocal fatigue. Physiologically, this indicated either a significantly shorter (anteroposteriorly) or a wider (transversely) glottis after vocal fatigue.
  
  
  CONCLUSIONS
  The high-speed imaging technique using quantitative analysis has the potential for early identification of vocally fatigued voice.
authors.affiliation: Voice Research Laboratory, Division of Speech & Hearing Sciences, The University of Hong Kong, Pokfulam, Hong Kong, China. Electronic address: eyiu@hku.hk.
authors.forename: Edwin M-L
authors.initials: EM
authors.lastname: Yiu
authors.forename: Gaowu
authors.initials: G
authors.lastname: Wang
authors.forename: Andy C Y
authors.initials: AC
authors.lastname: Lo
authors.forename: Karen M-K
authors.initials: KM
authors.lastname: Chan
authors.forename: Estella P-M
authors.initials: EP
authors.lastname: Ma
authors.forename: Jiangping
authors.initials: J
authors.lastname: Kong
authors.forename: Elizabeth Ann
authors.initials: EA
authors.lastname: Barrett
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D007828:Laryngoscopy; D008297:Male; D015203:Reproducibility of Results; D063346:Singing; D013061:Speech Acoustics; D014827:Vocal Cords / Q000503:physiopathology*; D014832:Voice Disorders / Q000175:diagnosis* / Q000503:physiopathology; D055815:Young Adult
keywords: Amateur singing; High-speed imaging; Vocal fatigue