Kymographic Imaging O Oscillatio

Kymographic imaging represents a method of viewing vocal fold oscillations, which is alternative to the routinely used frame-by-frame playback of the video recordings. Instead of video images of the whole vocal folds, in kymography images at only a single line are recorded. The successively recorded line-images are put together to create the resulting kymographic image. This image displays vibratory behavior at the selected part of the vocal folds. The paper briefly reviews four kymographic methods: photokymography, videokymography, videostrobokymography and high-speed digital kymography; and demonstrates the relationship between the kymographic vibratory pattern and the vibratory pattern of the vocal folds known from traditional laryngoscopy. Factors such as the selected position of the active line and the intended type of voice are pointed out to be important in evaluation of the vocalfold vibratory pattern displayed in kymographic images. Applications in which kymographic imaging has been found helpful are, for instance, evaluation of the microdynamics of the glottal oscillatory cycles, glottal onset and offset, glottal tremor, abduction and adduction speed or measurement of resonance properties of the laryngeal tissues.