title: A randomized controlled trial of stretch-and-flow voice therapy for muscle tension dysphonia.
abstract: OBJECTIVE
  To investigate the effect of stretch-and-flow voice therapy on vocal function and handicap.
  
  
  METHODS
  Randomized controlled trial.
  
  
  METHODS
  Participants with primary muscle tension dysphonia were randomly assigned to experimental or control groups. Experimental participants received vocal hygiene education followed by 6 weeks of stretch-and-flow voice therapy. Control participants received vocal hygiene education only. Outcome variables consisted of a measure of vocal handicap (Voice Handicap Index [VHI]), maximum phonation time, s/z ratio, and acoustic measures. All measures were obtained at baseline prior to treatment and within 2 weeks posttreatment or at the end of the control period. The pre- to posttreatment measurement change (delta Δ) was applied to statistical analyses.
  
  
  RESULTS
  A multivariate analysis of variance revealed significant group differences in pre-to-post changes on measures of VHI, maximum phonation time, and cepstral peak prominence (CPP) in connected speech and vowels (P = 0.003, 0.013, 0.025, and 0.017 respectively), with a significant reduction of VHI (Cohen's d = 1.6), increase in maximum phonation time (Cohen's d = 1.2), increase of CPP in connected speech (Cohen's d = 1.2), and increase of CPP in vowels (Cohen's d = 1.1) in the experimental group compared to the control group.
  
  
  CONCLUSIONS
  This preliminary small sample randomized controlled trial found significantly greater improvement in vocal handicap, maximum phonation time, and acoustic measures of vocal function after participants received stretch-and-flow voice therapy compared to participants receiving vocal hygiene education alone. Additional research incorporating larger samples will be needed to confirm and further investigate these findings.
  
  
  METHODS
  1b.
authors: Department of Communication Sciences and Disorders, Texas Christian University, Fort Worth.
authors: Christopher R
authors: CR
authors: Watts
authors: Clinical Center for Voice Care, Dept. of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A.
authors: Amy
authors: A
authors: Hamilton
authors: Clinical Center for Voice Care, Dept. of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A.
authors: Laura
authors: L
authors: Toles
authors: Clinical Center for Voice Care, Dept. of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A.
authors: Lesley
authors: L
authors: Childs
authors: Clinical Center for Voice Care, Dept. of Otolaryngology-Head and Neck Surgery, University of Texas Southwestern Medical Center, Dallas, Texas, U.S.A.
authors: Ted
authors: T
authors: Mau
mesh_terms: D055154:Dysphonia / Q000503:physiopathology / Q000534:rehabilitation*; D005260:Female; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D010699:Phonation / Q000502:physiology; D016896:Treatment Outcome; D014834:Voice Training
keywords: Dysphonia; flow phonation; muscle tension dysphonia; stretch-and-flow; vocal handicap; voice handicap index; voice therapy