A stroboscopy and high-speed videoendoscopy assessment of the relationship of vocal fold vibratory features in vocally-normal speakers

Heather Shaw Bonilha, Joanna Piasecki Whiteside, Dimitar D. Deliyski

The objectives of this study were to preliminarily ascertain the relationships between several diagnostically-relevant features of vocal fold vibration for normophonic speakers as assessed via stroboscopy and high-speed videoendoscopy (HSV) and to compare findings across modal and pressed phonations.
Methods: A correlational design was used, with factor analysis to determine grouping of features and cluster analysis to evaluate the role of age and gender on the relationships. Judgments of longitudinal and horizontal symmetry, open quotient, mucosal wave, vertical motion, period and width regularity, and glottal width were used for the correlational, factorial, and cluster analyses.
Results demonstrate a number of significant relationships between the vibratory features. This study is the first to empirically demonstrate the relationships between regularity and symmetry, and mucosal wave and vertical motion. This holds significance for our understanding of vocal fold physiology and visual perceptual rating of vibration. This data is also important for developing future perceptual and objective assessments for HSV. HSV revealed more, stronger relationships than stroboscopy for all features except the relationships between horizontal asymmetry and mucosal wave magnitude and asymmetry. As expected given the increased temporal resolution of the technique, HSV also revealed stronger relationships than stroboscopy for regularity. The decrease in the relationship of regularity to other features from pressed to habitual phonation reflects the atypical use of the mechanism for pressed phonation. Similarly, the relationships of vertical motion with other vibratory features increased for pressed versus habitual phonation revealing the influence of the increased air pressure on the vibratory features.

Heather Shaw Bonilha, Joanna Piasecki Whiteside, Dimitar D. Deliyski
Communication Sciences and Disorders
University of South Carolina
1621 Greene Street, 6th floor
Columbia, SC 29208, USA
Tel: (803) 777-4822 Fax: (803) 777-3081
shawhs@gwm.sc.edu
joannapw@gmail.com
ddeliyski@sc.edu