Changes in Articulator Movement Variability During Phonemic Development: A Longitudinal Study Purpose The present study explored articulator movement variability during voicing contrast acquisition. The purpose was to examine whether oral articulator movement trajectories associated with the production of voiced/voiceless bilabial phonemes in children became less variable over time. Method Jaw, lower lip, and upper lip movements were recorded longitudinally ... Research Article
Research Article  |   February 01, 2009
Changes in Articulator Movement Variability During Phonemic Development: A Longitudinal Study
 
Author Affiliations & Notes
  • Maria I. Grigos
    New York University
  • Contact author: Maria I. Grigos, Department of Speech Language Pathology and Audiology, New York University, 665 Broadway, Suite 918, New York, NY 10003. E-mail: maria.grigos@nyu.edu.
Article Information
Speech, Voice & Prosody / Speech / Research Articles
Research Article   |   February 01, 2009
Changes in Articulator Movement Variability During Phonemic Development: A Longitudinal Study
Journal of Speech, Language, and Hearing Research, February 2009, Vol. 52, 164-177. doi:10.1044/1092-4388(2008/07-0220)
History: Received September 17, 2007 , Accepted April 7, 2008
 
Journal of Speech, Language, and Hearing Research, February 2009, Vol. 52, 164-177. doi:10.1044/1092-4388(2008/07-0220)
History: Received September 17, 2007; Accepted April 7, 2008
Web of Science® Times Cited: 21

Purpose The present study explored articulator movement variability during voicing contrast acquisition. The purpose was to examine whether oral articulator movement trajectories associated with the production of voiced/voiceless bilabial phonemes in children became less variable over time.

Method Jaw, lower lip, and upper lip movements were recorded longitudinally in six, 19 month-old children as they began producing the voiceless phoneme /p/. Displacement signals were time and amplitude normalized. The spatiotemporal index (A. Smith, L. Goffman, H. Zelaznik, S. Ying, & C. McGillem, 1995) was computed to examine the variability in movement trajectories across repeated productions of target utterances.

Results Spatiotemporal variability of lip and jaw movements significantly decreased as children began producing the voiceless phoneme /p/. A significant negative correlation between the STI and the length of voice onset time (VOT) was also found in the voiceless productions in 4 of the 6 participants.

Conclusions Oral articulator movement variability is reduced in children across the stabilization of voicing contrast acquisition. Further, the relationship between VOT contrast production and movement variability suggests that a coordinate system between the oral and laryngeal articulators may be refined as children acquire the voicing contrast.

Order a Subscription
Pay Per View
Entire Journal of Speech, Language, and Hearing Research content & archive
24-hour access
This Article
24-hour access