title: [A contrast analysis of four phonation methods frequency between patients with glottis closure disturbance and normal human].
abstract: OBJECTIVE
  To find out frequency change parameters of four phonation methods (minimum, natural, maximum and falsetto maximum voices) and different maximum phonation persistent time (MPPT) of them in patients with glottis closure disturbance (GCD).
  
  
  METHODS
  With frequency spectrum analysis, the frequencies of four phonation methods were studied in functional GCD patients (150 cases) and normal human (60 cases).
  
  
  RESULTS
  There were marked differences of voice frequencies between them not only in male but also in 5 female. And with the prolongation of MPPT, the voice frequencies also changed.
  
  
  CONCLUSIONS
  The functions of both low and high voices decline in GCD patients. With the prolongation of MPPT, the functions of low and high voices strengthen in GCD patients.
authors.affiliation: Second Hospital of China Medical University, Shenyang 110003.
authors.forename: J
authors.initials: J
authors.lastname: Li
authors.forename: S L
authors.initials: SL
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005931:Glottis / Q000473:pathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010699:Phonation / Q000502:physiology*; D013018:Sound Spectrography