title: Phonation threshold flow measurements in normal and pathological phonation.
abstract: OBJECTIVE
  Phonation threshold flow (PTF) may provide a tool to assess laryngeal function and could differentiate between normal and pathological voices. Both polyps and nodules contribute to an increased PTF by creating an incomplete glottal closure and increased vocal fold mass and thickness.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  The Kay Elemetrics Phonatory Aerodynamic System (PAS) (Kay Elemetrics Corp., Lincoln Park, NJ) was used to collect mean flow rate (MFR) and PTF measurements from 40 normal subjects, 21 patients with vocal fold nodules, and 23 patients with vocal fold polyps. Gender-based differences were assessed using a t test. The effect of vocal pathology on PTF and MFR was determined with an ANOVA. Diagnostic potential was evaluated using a receiver operation characteristics (ROC) analysis.
  
  
  RESULTS
  Both PTF (P = .047) and MFR (P = .008) were significantly affected by gender. Using a two-way ANOVA and correcting for gender differences, the influence of pathology on PTF was determined to be significant (P < .001). Post hoc tests found a significant difference between normal and polyp subjects (P < .001) but not normal and nodule subjects (P = .177) or nodule and polyp subjects (P = .246). ROC analysis found that PTF (area under the curve [AUC] = 0.691) and MFR (AUC = 0.684) had a similar diagnostic utility.
  
  
  CONCLUSIONS
  PTF can be used to differentiate between normal and pathological voices. As a parameter that is experimentally sensitive to the biomechanical parameters providing its theoretical basis, it could be used clinically to analyze laryngeal functionality. Future research could focus on measuring PTF in other pathologies, such as paralysis or scarring, which would also affect the effort required to produce voice.
authors.affiliation: Department of Surgery, Division of Otolaryngology-Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, USA.
authors.forename: Peiyun
authors.initials: P
authors.lastname: Zhuang
authors.forename: Alicia J
authors.initials: AJ
authors.lastname: Sprecher
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Hoffman
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhang
authors.forename: Marios
authors.initials: M
authors.lastname: Fourakis
authors.forename: Jack J
authors.initials: JJ
authors.lastname: Jiang
authors.forename: Chun Sheng
authors.initials: CS
authors.lastname: Wei
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D004056:Differential Threshold; D005260:Female; D006801:Humans; D007818:Laryngeal Diseases / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D010699:Phonation / Q000502:physiology*; D011446:Prospective Studies; D012372:ROC Curve; D012016:Reference Values; D012727:Sex Characteristics; D014827:Vocal Cords / Q000503:physiopathology*; D014832:Voice Disorders / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology*