title: Parameters acoustic and high-speed kymography identified effects of voiced vibration and vocal fry exercises.
abstract: OBJECTIVE
  To identify the immediate effects of voiced vibration and vocal fry exercises on healthy subjects by means of acoustic parameters and high-speed kymography.
  
  
  METHODS
  Thirty healthy subjects (18 women and 12 men, aged from 19 to 45 years old) participated in this study. The voices were recorded at the range of 44.100 samples/second, before and after of the vocal exercises. We developed a computational routine to extract jitter and shimmer. High-speed kymography was generated from laryngeal images for the analysis of the phase times: closed (CPh), open (OPh), of closing (cPh) and of opening (oPh) and used the paired t-Student test and the Mann-Whitney test, with a significance level of 0.05.
  
  
  RESULTS
  After voiced vibrations, acoustic parameters showed reduced jitter for both genders (p=0.018 for men and p<0.01 for women) and reduced shimmer for female voices (p<0.01). There was a decrease in CPh (p=0.046) and cPh (p=0.026) and an increase in OPh (p=0.05) in female vocal folds. After vocal fry, we identified decreased jitter (p<0.01) in female voices and cPh (p=0.026) in male vocal folds.
  
  
  CONCLUSIONS
  We observed more positive immediate effects of the voiced vibrations, mainly in voice quality and vocal folds among females. Nevertheless, studies with larger male sample and investigation of the appropriate time of vocal fry are necessary to confirm the results of this search.
authors.affiliation: Universidade de São Paulo, Engineering School of São Carlos, São CarlosSP, Brazil, Engineering School of São Carlos, Universidade de São Paulo - USP - São Carlos (SP), Brazil.
authors.forename: Regina Aparecida
authors.initials: RA
authors.lastname: Pimenta
authors.affiliation: Universidade de São Paulo, School of Medicine, São PauloSP, Brazil, School of Medicine, Universidade de São Paulo - USP - São Paulo (SP), Brazil.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Dájer
authors.affiliation: Universidade de São Paulo, School of Medicine, São PauloSP, Brazil, School of Medicine, Universidade de São Paulo - USP - São Paulo (SP), Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: Hachiya
authors.affiliation: Universidade de São Paulo, School of Medicine, São PauloSP, Brazil, School of Medicine, Universidade de São Paulo - USP - São Paulo (SP), Brazil.
authors.forename: Domingos Hiroshi
authors.initials: DH
authors.lastname: Tsuji
authors.affiliation: Universidade de São Paulo, Engineering School of São Carlos, São CarlosSP, Brazil, Engineering School of São Carlos, Universidade de São Paulo - USP - São Carlos (SP), Brazil.
authors.forename: Arlindo Neto
authors.initials: AN
authors.lastname: Montagnoli
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D007734:Kymography; D008297:Male; D008875:Middle Aged; D012737:Sex Factors; D014732:Vibration; D014827:Vocal Cords / Q000502:physiology*; D014833:Voice Quality / Q000502:physiology*; D055815:Young Adult