Videokymography: research and clinical issues

Stroboscopy is based on the assumption that the vibration is stable and regular. Irregular vibrations, as is often the case in voice pathology, cannot easily be studied by stroboscopy. Videokymography overcomes this drawback. Videokymography, using a modified CCD video camera, makes it possible to observe all kinds of regular and irregular vocal fold vibrations, including those leading to pathological voice productions, It easily visualises small left-right asymmetries, open and closed phases of the selected part of the glottis, lateral propagation of mucosal waves, movements of the upper margin and, in the closing phase, the lower margin of the vocal folds. This is advantageous for a more accurate diagnosis of voice disorders. Also other fields which study mechanical vibrations, like strings of musical instruments, may benefit from videokymography.