title: Materials of acoustic analysis: sustained vowel versus sentence.
abstract: OBJECTIVE
  Sustained vowel is a widely used material of acoustic analysis. However, vowel phonation does not sufficiently demonstrate sentence-based real-life phonation, and biases may occur depending on the test subjects intent during pronunciation. The purpose of this study was to investigate the differences between the results of acoustic analysis using each material.
  
  
  METHODS
  An individual prospective study.
  
  
  METHODS
  Two hundred two individuals (87 men and 115 women) with normal findings in videostroboscopy were enrolled. Acoustic analysis was done using the speech pattern element acquisition and display program. Fundamental frequency (Fx), amplitude (Ax), contact quotient (Qx), jitter, and shimmer were measured with sustained vowel-based acoustic analysis. Average fundamental frequency (FxM), average amplitude (AxM), average contact quotient (QxM), Fx perturbation (CFx), and amplitude perturbation (CAx) were measured with sentence-based acoustic analysis. Corresponding data of the two methods were compared with each other. SPSS (Statistical Package for the Social Sciences, Version 12.0; SPSS, Inc., Chicago, IL) software was used for statistical analysis.
  
  
  RESULTS
  FxM was higher than Fx in men (Fx, 124.45 Hz; FxM, 133.09 Hz; P=0.000). In women, FxM seemed to be lower than Fx, but the results were not statistically significant (Fx, 210.58 Hz; FxM, 208.34 Hz; P=0.065). There was no statistical significance between Ax and AxM in both the groups. QxM was higher than Qx in men and women. Jitter was lower in men, but CFx was lower in women. Both Shimmer and CAx were higher in men.
  
  
  CONCLUSIONS
  Sustained vowel phonation could not be a complete substitute for real-time phonation in acoustic analysis. Characteristics of acoustic materials should be considered when choosing the material for acoustic analysis and interpreting the results.
authors.affiliation: Department of Otorhinolaryngology, Head and Neck Surgery, School of Medicine, Ewha Womans University, 911-1 Mok-Dong, Yang Cheon-Gu, Seoul 158-710, Korea.
authors.forename: Kyung Ray
authors.initials: KR
authors.lastname: Moon
authors.forename: Sung Min
authors.initials: SM
authors.lastname: Chung
authors.forename: Hae Sang
authors.initials: HS
authors.lastname: Park
authors.forename: Han Su
authors.initials: HS
authors.lastname: Kim
mesh_terms: D000162:Acoustics; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010363:Pattern Recognition, Automated; D010699:Phonation; D011446:Prospective Studies; D012815:Signal Processing, Computer-Assisted; D013061:Speech Acoustics; D013068:Speech Production Measurement / Q000379:methods*; D049489:Stroboscopy; D013997:Time Factors; D014741:Video Recording; D014833:Voice Quality; D055815:Young Adult