Abstract
Objectives:
Investigate the correlation between vocal cord vibration parameters and aerodynamic parameters.
Methods:
We examined 13 patients with various voice disorders. Using the phonatory function analyzer PS77E, we measured sound pressure level (SPL), mean flow rate (MFR), expiratory lung pressure (EP), and airway resistance (EP/MFR). We used a high-speed video (HSV) system to observe the vocal cord vibration. We obtained the image data at a speed of 2000 frames/sec, while each subject was vocalizing the vowel sound /a/. We analyzed the predetermined area using Kay Image Processing Software (KIPS) with regard to the following: 1) maximum or minimum area, maximum or minimum opening at the midpoint of the glottis from a montage with glottal area waveform (GAW) analysis, and 2) maximum or minimum opening of the glottis, dominant amplitude or frequency of the opening variation of the vocal fold, and ratio of time of glottal total closure to the entire time domain in the calculation using kymograph edge analysis (KEA). Spearman’s rank correlation was used to determine correlations.
Results:
A correlation existed between sound pressure and posterior glottal vibration as assessed by KEA (left: P = 0.0199 and right: P = 0.0372) and central glottal vibration (left: P = 0.022 and right: P = 0.0438). Neither GAW nor KEA was correlated with both expiratory flow rate and expiratory pressure. A negative correlation was seen between airway resistance and GAW minimum opening (P = 0.0256).
Conclusions:
The results of the present study suggest that vocal cord parameters correlate with aerodynamic parameters.
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