Fundamental Frequency, Closed Quotient, Jitter, and Shimmer of Vowels on Electroglottography

Kim, Jaeock

ORIGINAL ARTICLE

Commun Sci Disord. 2011;16(4): 449-459.

Jaeock Kim^`

김재옥(Jaeock Kim)

ABSTRACT

Background & Objectives
Laryngeal function is affected by supralaryngeal (vocal tract) shape and size during speech. The previous studies investigating the laryngeal changes among vowels did not have coherent conclusions. The purpose of the present study was to investigate the influence of vowel context on laryngeal function measured by electroglottography (EGG).
Method
Thirty-six normal adult men and 36 normal adult women prolonged the vowels /a/, /e/, /o/, /i/, /u/ at a comfortable level. The vowels were recorded by EGG and analyzed with fundamental frequency (Fo), closed quotient (CQ), jitter, and shimmer.
Results
Fo, CQ, jitter, and shimmer were significantly different according to the vowel: vowels /i/ and /u/ had highervalues than the low vowel /a/ in Fo, CQ, and shimmer, but vice versa for jitter.
Discussion & Conclusion
By comparing previous studies with the present study, vowel context was shown to strongly affect the intrinsic pitch of vowels and vocal frequency perturbation by changing vocal configuration, although providing negligible effect on glottal closure and vocal amplitude perturbation.