title: Perceptual analysis of adolescents' vocal stability during different phonation tasks.
abstract: BACKGROUND
  Quality and frequency variability of adolescents' voice, during puberty, in different phonation tasks.
  
  
  OBJECTIVE
  To analyze the vocal stability of adolescents in three different phonation tasks using a voice perceptual analysis.
  
  
  METHODS
  Participants were male students (n = 46 individuals), ranging in age from 13 to 15 years, from a public school in Campinas--SP. Voice samples were recorded using a digital recorder in three different tasks: speaking a sustained vowel /a/, counting from one to ten, and reading. Three voice specialists evaluated stability by means of voice perceptual analysis. For the voice samples that were considered unstable, the Analogical Visual Scale (AVS) of 10 cm was used to estimate the instability level, where zero means absence of instability and ten refers to maximum instability.
  
  
  RESULTS
  78.3% of the adolescents presented vocal instability when speaking the sustained vowel, varying from one to nine in the AVS. Only one adolescent presented unstable voice when counting numbers (level = 1). Vocal instability was not observed during reading for any of the participants. Vocal stability varied significantly among phonation tasks and adolescents showed greater instability during the sustained vowel (p<0.0001; g.l = 2).
  
  
  CONCLUSIONS
  Counting numbers and reading do not detect vocal instability; the production of a sustained vowel demonstrated to be a better task.
authors.affiliation: Universidade Federal do Pará. guima.michelle@gmail.com
authors.forename: Michelle Ferreira
authors.initials: MF
authors.lastname: Guimarães
authors.forename: Mara Suzana
authors.initials: MS
authors.lastname: Behlau
authors.forename: Ivone
authors.initials: I
authors.lastname: Panhoca
mesh_terms: D000293:Adolescent; D016009:Chi-Square Distribution; D006801:Humans; D008297:Male; D010699:Phonation / Q000502:physiology*; D011627:Puberty / Q000502:physiology; D013061:Speech Acoustics; D013067:Speech Perception; D013068:Speech Production Measurement; D014833:Voice Quality