title: Articulation rate and vowel space characteristics of young males with fragile X syndrome: preliminary acoustic findings.
abstract: OBJECTIVE
  Increased speaking rate is a commonly reported perceptual characteristic among males with fragile X syndrome (FXS). The objective of this preliminary study was to determine articulation rate-one component of perceived speaking rate-and vowel space characteristics of young males with FXS.
  
  
  METHODS
  Young males with FXS (n = 38), developmental age (DA)-matched males (n = 21), and chronological age (CA)-matched males (n = 16) were audiotaped while engaged in spontaneous conversation and a picture-naming task. Articulation rate in syllables per second during intelligible utterances and vowel space area/dispersion measures were acoustically determined for each speaker.
  
  
  RESULTS
  Males with FXS did not articulate significantly faster than CA-matched males. Area and dispersion of the acoustic vowel space also were similar between the 2 groups. Males with FXS, however, used significantly shorter utterances and had a tendency to pause less often than CA-matched males. In addition, males with FXS exhibited greater intraspeaker variability of formants associated with the vowel /a/.
  
  
  CONCLUSIONS
  These preliminary findings suggest that articulation rate may not be a primary factor contributing to perceived speaking rate of males with FXS. Limitations of the study relative to speech production tasks and utterance intelligibility are discussed.
authors.affiliation: University of North Carolina Craniofacial Center, CB# 7450, Chapel Hill, NC 27599, USA. david_zajac@dentistry.unc.edu
authors.forename: David J
authors.initials: DJ
authors.lastname: Zajac
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Roberts
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Hennon
authors.forename: Adrianne A
authors.initials: AA
authors.lastname: Harris
authors.forename: Elizabeth F
authors.initials: EF
authors.lastname: Barnes
authors.forename: Jan
authors.initials: J
authors.lastname: Misenheimer
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005600:Fragile X Syndrome / Q000150:complications / Q000503:physiopathology*; D006801:Humans; D008297:Male; D015999:Multivariate Analysis; D010700:Phonetics; D013061:Speech Acoustics; D013064:Speech Disorders / Q000209:etiology / Q000503:physiopathology*; D013065:Speech Intelligibility; D013068:Speech Production Measurement; D013637:Tape Recording