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 CQEGG was calculated from a sustained vowel phonation in three different phonation types (breathy, normal, pressed) at three amplitude threshold levels (25%, 35%, 50%). CQEGG 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 CQEGG 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 CQEGG were not significant.
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.