title: Phonation Quotient in Women: A Measure of Vocal Efficiency Using Three Aerodynamic Instruments.
abstract: OBJECTIVE
  The purpose of this study was to examine measures of vital capacity and phonation quotient across three age groups in women using three different aerodynamic instruments representing low-tech and high-tech options.
  
  
  METHODS
  This study has a prospective, repeated measures design.
  
  
  METHODS
  Fifteen women in each age group of 25-39 years, 40-59 years, and 60-79 years were assessed using maximum phonation time and vital capacity obtained from three aerodynamic instruments: a handheld analog windmill type spirometer, a handheld digital spirometer, and the Phonatory Aerodynamic System (PAS), Model 6600. Phonation quotient was calculated using vital capacity from each instrument. Analyses of variance were performed to test for main effects of the instruments and age on vital capacity and derived phonation quotient. Pearson product moment correlation was performed to assess measurement reliability (parallel forms) between the instruments. Regression equations, scatterplots, and coefficients of determination were also calculated.
  
  
  RESULTS
  Statistically significant differences were found in vital capacity measures for the digital spirometer compared with the windmill-type spirometer and PAS across age groups. Strong positive correlations were present between all three instruments for both vital capacity and derived phonation quotient measurements.
  
  
  CONCLUSIONS
  Measurement precision for the digital spirometer was lower than the windmill spirometer compared with the PAS. However, all three instruments had strong measurement reliability. Additionally, age did not have an effect on the measurement across instruments. These results are consistent with previous literature reporting data from male speakers and support the use of low-tech options for measurement of basic aerodynamic variables associated with voice production.
authors.affiliation: Department of Communication Sciences and Disorders, University of Houston, 4455 Cullen Blvd, Houston, Texas. Electronic address: ajoshi4@uh.edu.
authors.forename: Ashwini
authors.initials: A
authors.lastname: Joshi
authors.affiliation: Harris College of Nursing & Health Sciences, TCU Box 297450, Fort Worth, TX 76129.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Watts
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D004867:Equipment Design; D005260:Female; D006801:Humans; D007830:Larynx / Q000502:physiology*; D008168:Lung / Q000502:physiology*; D008875:Middle Aged; D010699:Phonation; D011237:Predictive Value of Tests; D011446:Prospective Studies; D015203:Reproducibility of Results; D013147:Spirometry / Q000295:instrumentation*; D014797:Vital Capacity; D014833:Voice Quality
keywords: aerodynamics; phonation quotient; spirometer; vital capacity; vocal efficiency