title: Systematic studies of modified vocalization: the effect of speech rate on speech production measures during metronome-paced speech in persons who stutter.
abstract: BACKGROUND
  Metronome-paced speech results in the elimination, or substantial reduction, of stuttering moments. The cause of fluency during this fluency-inducing condition is unknown. Several investigations have reported changes in speech pattern characteristics from a control condition to a metronome-paced speech condition, but failure to control speech rate between conditions limits our ability to determine if the changes were necessary for fluency.
  
  
  OBJECTIVE
  This study examined the effect of speech rate on several speech production variables during one-syllable-per-beat metronomic speech in order to determine changes that may be important for fluency during this fluency-inducing condition.
  
  
  METHODS
  Thirteen persons who stutter (PWS), aged 18-62 years, completed a series of speaking tasks. Several speech production variables were compared between conditions produced at different metronome beat rates, and between a control condition and a metronome-paced speech condition produced at a rate equal to the control condition.
  
  
  RESULTS
  Vowel duration, voice onset time, pressure rise time and phonated intervals were significantly impacted by metronome beat rate. Voice onset time and the percentage of short (30-100 ms) phonated intervals significantly decreased from the control condition to the equivalent rate metronome-paced speech condition.
  
  
  CONCLUSIONS
  A reduction in the percentage of short phonated intervals may be important for fluency during syllable-based metronome-paced speech for PWS. Future studies should continue examining the necessity of this reduction. In addition, speech rate must be controlled in future fluency-inducing condition studies, including neuroimaging investigations, in order for this research to make a substantial contribution to finding the fluency-inducing mechanism of fluency-inducing conditions.
authors.affiliation: Department of Speech-Language-Hearing Sciences, Hofstra University, Hempstead, NY, USA.
authors.forename: Jason H
authors.initials: JH
authors.lastname: Davidow
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010699:Phonation / Q000502:physiology; D010700:Phonetics; D015203:Reproducibility of Results; D013061:Speech Acoustics; D013068:Speech Production Measurement / Q000295:instrumentation* / Q000379:methods* / Q000592:standards; D013070:Speech Therapy / Q000295:instrumentation* / Q000379:methods* / Q000592:standards; D013342:Stuttering / Q000175:diagnosis* / Q000503:physiopathology*; D055815:Young Adult
keywords: fluency-inducing conditions; metronome; phonated intervals; stuttering