Electroglottographic evaluation of age and gender effects during sustained phonation and connected speech

The aim of the present study was to evaluate the effects of age and gender on selected vocal fold vibratory behaviors during vowel prolongation and connected speech using electroglottography (EGG). Forty-six young and older individuals (23 males and 23 females) with normal voices participated in this study. EGG parameters including fundamental frequency and contact quotient were measured during sustained vowel prolongation and connected speech tasks. Significant age-by-gender interactions were found for both parameters. Moreover, results from discriminant function analyses revealed that the overall accuracies of the parameters in predicting different age and gender groups were higher for the connected speech tasks than for the sustained vowel prolongation task (89.1% and 73.9% for passage and phrase tasks vs 71.7% for vowel prolongation). These findings suggest that reliability of EGG measures can be affected by the test stimuli. Therefore, one should carefully consider the use of the speech material when assessing vocal fold behaviors using EGG. The findings also support the use of connected speech stimulus, preferably at passage level, in electroglottographic evaluation for a better representation of vocal fold vibrating behaviors.