The Useful Parameters of Videokymography

Ahn, Cheol Min; Chung, Duk Hee; Choi, Ji Ho

Abstract

BACKGROUND AND OBJECTIVES: Voice quality is determined by the vibration of the vocal cord. Therefore, visualization of the vibratory characteristics of the vocal cord is very important in patients with voice changes. Several methods for directly visualizing the vibrations of the vocal cord have been developed, although none have been commercially available or widely used. Recently, videokymography (VKG) has been developed for direct observation of vibratory characteristics in the vocal cord. VKG achieves a frequency of 7812.5 Hz, which is enough to cover the whole frequency range of the human vocal cord. However, there have been no useful parameters for interpretation of the VKG findings.
MATERIALS AND METHODS
We evaluated the vocal cord vibration of 92 subjects (23 of normal, 69 of benign laryngeal lesion) and suggested 9 parameters. We analyzed VKG recordings of subjects using these parameters and interpreted the typical and common VKG findings in each case.
RESULTS
There were typical differences in glottal contact, site of glottal contact, shape of glottal contact, mucosal wave, periodicity and symmetry between two groups. Amplitude of upper lip and contact quotient had a highly significant correlation between them.
CONCLUSIONS
The authors suggest that these parameters would be useful to quantify the VKG findings.