Electroglottographic contact quotient in different phonation types using different amplitude threshold levels

Abstract

Contact quotient (CQ), measured by electroglottogram (EGG), is a ratio which illustrates the duration of vocal fold contact during one vocal fold period. In the present study CQ_EGG was calculated from a sustained vowel phonation in three different phonation types (breathy, normal, pressed) at three amplitude threshold levels (25%, 35%, 50%). CQ_EGG values were compared with experts’ perceptual evaluation of the firmness of phonation. The contact time of the vocal folds differed significantly between the different phonation types at all threshold levels (P < 0.01). Perceptual evaluation correlated best with CQ_EGG at threshold levels 25% and 35%. The results of the linear regression model suggested that by using threshold level 25% the effect of F0 and SPL on CQ_EGG were not significant.

Key words::

• Effect of F0 and SPL
• electroglottography
• perceptual evaluation
• threshold levels

Acknowledgements

This study was supported by the Academy of Finland (grant No. 1128095). The authors would especially like to thank senior laboratory technician Mr Jarmo Helin for assisting in the analyses of the material and Mrs Virginia Mattila, MA, for language correction of the manuscript.

Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.