Phase Asymmetries in Normophonic Speakers: Visual Judgments and Objective Findings Purpose To ascertain the amount of phase asymmetry of the vocal fold vibration in normophonic speakers via visualization techniques and compare findings for habitual and pressed phonations. Method Fifty-two normophonic speakers underwent stroboscopy and high-speed videoendoscopy (HSV). The HSV images were further processed into 4 visual displays: HSV ... Research Article
Research Article  |   November 01, 2008
Phase Asymmetries in Normophonic Speakers: Visual Judgments and Objective Findings
 
Author Affiliations & Notes
  • Heather Shaw Bonilha
    University of South Carolina, Columbia
  • Dimitar D. Deliyski
    University of South Carolina, Columbia
  • Terri Treman Gerlach
    Charlotte Eye, Ear, Nose, and Throat Associates, Charlotte, NC
  • Contact author: Heather Shaw Bonilha, Communication Sciences and Disorders, University of South Carolina, 1621 Greene Street, 6th Floor, Columbia, SC 29208. E-mail: shawhs@gwm.sc.edu.
Article Information
Speech, Voice & Prosodic Disorders / Voice Disorders / Speech, Voice & Prosody / Research Articles
Research Article   |   November 01, 2008
Phase Asymmetries in Normophonic Speakers: Visual Judgments and Objective Findings
American Journal of Speech-Language Pathology, November 2008, Vol. 17, 367-376. doi:10.1044/1058-0360(2008/07-0059)
History: Received August 1, 2007 , Accepted February 23, 2008
 
American Journal of Speech-Language Pathology, November 2008, Vol. 17, 367-376. doi:10.1044/1058-0360(2008/07-0059)
History: Received August 1, 2007; Accepted February 23, 2008
Web of Science® Times Cited: 42

Purpose To ascertain the amount of phase asymmetry of the vocal fold vibration in normophonic speakers via visualization techniques and compare findings for habitual and pressed phonations.

Method Fifty-two normophonic speakers underwent stroboscopy and high-speed videoendoscopy (HSV). The HSV images were further processed into 4 visual displays: HSV playbacks, digital kymography (DKG) playbacks, mucosal wave kymography playbacks, and static kymographic images of the medial line from the DKG playback. Two types of phase asymmetries, left-right and anterior-posterior, were rated on a scale from 1 to 5. Objective measures of left-right phase asymmetry were obtained.

Results The majority of normophonic speakers (81%) were noted to display anterior-posterior asymmetry; however, 66% of those were characterized as mild. Seventy-nine percent of participants were noted to display left-right asymmetry; however, 72% of those were mild. A moderate relationship between the objective measures and subjective ratings was found.

Conclusions Most normophonic speakers exhibit mild left-right and anterior-posterior asymmetries for both habitual and pressed phonations. Asymmetries were noted more often during habitual than pressed phonations, and when visualized by HSV and kymography than stroboscopy. Differences between objective measures and visual judgments support the need to quantify vocal fold vibratory features.

Acknowledgments
This project was supported by Research Grant No. 11560-KA01 funded by the University of South Carolina Research Foundation and Research Grant No. R01 DC007640 funded by the National Institute of Deafness and Other Communication Disorders. The authors express their appreciation to Cara Sauder for her help with data collection, and to Drs. Allen Montgomery, Hiram McDade, and Gary Allen, who provided insight to strengthen this study. Portions of this study were presented at the Voice Foundation’s 34th Annual Symposium: Care of the Professional Voice, Philadelphia, June 2005.
Order a Subscription
Pay Per View
Entire American Journal of Speech-Language Pathology content & archive
24-hour access
This Article
24-hour access