Hitoshi Toda

High-Speed Camera Observations of Vocal Nodules

Objective: We compared the vocal fold vibration pattern among normal subjects and vocal nodules. Observation of the movement to the vocal cord mucosa using a high speed camera, examining a mechanism of abnormal vibration by observing the motion of the vocal process was intended to clarify the cause of vocal nodules. Method: Five normal speech and 8 patients with vocal nodules were compared. High-speed cameras recorded the vocal cord vibration. Easy phonation, 3000 fps or 3333 fps. We are in the position of the vocal process 3 consecutive images of the period, direction, investigated the symmetry of left and right. Results: In normal vocal cords vocal process was symmetrical. (5/5 case) Swings from side to side width and vocal process was about the same for both sides. The direction of extension of the vocal process was assembled in the center of the vocal cords membranes. (5/5 case) The midline of the laryngeal vocal nodules vocal process was in a different position on the left and right (7/8 case). Swings were different width of the vocal process (6/8 case). The direction of extension of the right and left vocal process was different. Conclusion: In the normal group, parallel to the vocal cords vibrate in contact throughout the mucosa. Vocal nodule group was lateralized position of the vocal process. We thought to focus on one part of the mucous membrane contact between vocal cords. It was considered one of the pathogenesis of vocal nodules.