Schematical presentation of vibration of the vocal cord as a layer-structured vibrator

Abstract

Vibratory mode of the vocal cord in normal conditions was investigated by frame-by-frame analysis of ultra high speed motion pictures. On the basis of the data obtained from the films, as well as those obtained from some laryngograms, histological findings and measurements of stiffness, movements of the vocal cord in a frontal section, within one vibratory cycle, were schematically presented where the vocal cord was regarded as a double-layered vibrator. The present paper describes the experimental and theoretical basis and the procedures to schematize vibratory movements of the vocal cord having a layered structure. Two normal examples, one in a heavy register and the other in a light register, were also presented and some comparisons were made between the two registers. This type of schematization appears significant not only to explain the vibratory movements in various conditions but also to simulate vocal cord vibrations. © 1976, The Oto-Rhino-Laryngological Society of Japan, Inc. All rights reserved.