On the next sites you see videoclips of one vocal mode changing into another vocal mode. The videos are taken using a flexible endoscope inserted via the nose. Stroboscopic light is used so the vibration of the vocal folds can be seen in slow motion. The flashing of the stroboscopic light is triggered using the Laryngograph signal. This is obtained by placing two electrodes placed on the neck over the larynx and the waveform can be seen as a a green moving line at the bottom of the image. When the vocal folds are vibrating and touch each other the green line rises and when they peel apart the line falls creating the change in shape of the waveform.
The videos are from the endoscopy study performed by Julian McGlashan and Cathrine Sadolin at CVI in Copenhagen in June 2007.