title: Acoustic and articulatory features of diphthong production: a speech clarity study.
abstract: OBJECTIVE
  The purpose of this study was to evaluate how speaking clearly influences selected acoustic and orofacial kinematic measures associated with diphthong production.
  
  
  METHODS
  Forty-nine speakers, drawn from the University of Wisconsin X-Ray Microbeam Speech Production Database (J. R. Westbury, 1994), served as participants. Samples of clear and conversational productions of the word combine were extracted for analysis. Analyses included listener ratings of speech clarity and a number of acoustic and articulatory kinematic measures associated with production of the diphthong /aI/.
  
  
  RESULTS
  Key results indicate that speaking clearly is associated with (a) increased duration of diphthong-related acoustic and kinematic events, (b) larger F1 and F2 excursions and associated tongue and mandible movements, and (c) minimal evidence of change in formant transition rate.
  
  
  CONCLUSIONS
  Overall, the results suggest that clarity-related changes in diphthong production are accomplished through larger, longer, but not necessarily faster diphthong-related transitions. The clarity-related adjustments in diphthong production observed in this study conform to a simple model that assumes speech clarity arises out of reduced overlap of articulatory gestures.
authors: Department of Speech Pathology and Audiology, Western Michigan University, Kalamazoo, MI 49008, USA. Stephen.tasko@wmich.edu
authors: Stephen M
authors: SM
authors: Tasko
authors: Kristin
authors: K
authors: Greilick
mesh_terms: D000293:Adolescent; D000328:Adult; D000399:Air Pressure; D001696:Biomechanical Phenomena; D005260:Female; D006801:Humans; D007398:Interpersonal Relations; D008297:Male; D008334:Mandible / Q000502:physiology; D010700:Phonetics; D013018:Sound Spectrography; D013060:Speech / Q000502:physiology; D013061:Speech Acoustics; D013065:Speech Intelligibility; D013068:Speech Production Measurement; D013997:Time Factors; D014059:Tongue / Q000502:physiology; D055815:Young Adult