title: Acoustic and perceptual consequences of clear and loud speech.
abstract: OBJECTIVE
  Several issues concerning F2 slope in dysarthria were addressed by obtaining speech acoustic measures and judgments of intelligibility for sentences produced in Habitual, Clear and Loud conditions by speakers with Parkinson's disease (PD) and healthy controls.
  
  
  METHODS
  Acoustic measures of average and maximum F2 slope for diphthongs, duration and intensity were obtained. Listeners judged intelligibility using a visual analog scale. Differences in measures among groups and conditions as well as relationships among measures were examined.
  
  
  RESULTS
  Average and maximum F2 slope metrics were strongly correlated, but only average F2 slope consistently differed among groups and conditions, with shallower slopes for the PD group and steeper slopes for Clear speech versus Habitual and Loud. Clear and Loud speech were also characterized by lengthened durations, increased intensity and improved intelligibility versus Habitual. F2 slope and intensity were unrelated, and F2 slope was a significant predictor of intelligibility.
  
  
  CONCLUSIONS
  Average diphthong F2 slope was more sensitive than maximum F2 slope to articulatory mechanism involvement in mild dysarthria in PD. F2 slope holds promise as an objective measure of treatment-related changes in the articulatory mechanism for therapeutic techniques that focus on articulation.
authors: Department of Communicative Disorders and Sciences, Buffalo, N.Y., USA.
authors: Kris
authors: K
authors: Tjaden
authors: Emily
authors: E
authors: Richards
authors: Christina
authors: C
authors: Kuo
authors: Greg
authors: G
authors: Wilding
authors: Joan
authors: J
authors: Sussman
mesh_terms: D000368:Aged; D004401:Dysarthria / Q000175:diagnosis*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis*; D010700:Phonetics; D012016:Reference Values; D013018:Sound Spectrography; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013068:Speech Production Measurement