Schematical presentation of vibration of pathological vocal cords

Abstract

Vibratory mode of the vocal cords in seven different pathological conditions was investigated by frame-by-frame analysis of ultra high speed motion pictures. The pathological laryngeal conditions investigated were recurrent laryngeal nerve palsy, sulcus vocalis, polyp, polypoid vocal cord, amyloid tumor, epithelial hyperplasia, and carcinoma. On the basis of the data obtained movements of the vocal cord in a frontal section within one vibratory cycle in each pathological conditions were schematically presented where the vocal cord was regarded as a double layered vibrator. Furthermore, some comparisons of vibratory mode among the different conditions were studied with a special attention to the maximum amplitude and the maximum velocity of lateral excursion of the vocal cord, which are related to the mass, elasticity, viscosity, and interferences by the counterpart. © 1976, The Oto-Rhino-Laryngological Society of Japan, Inc. All rights reserved.