In the video example below notice the change of the character of the sound, the change in visual laryngeal appearance, and the change in visual laryngograph waveform appearance when the singer changes back and forth between the notes/modes.
The sound changes from Curbing to Edge
In the video example below notice the ‘restrained’ half metallic character of the sound in Curbing changing to the loud, scream-like full metallic character of the sound in Edge.
The visual laryngeal appearance
The laryngeal gestures changes from Curbing
In Curbing the false folds approach each other slightly, covering some (the lateral aspect) of the vocal folds. The front and the back of the laryngeal opening approach each other, making the angle acute between the aryepiglottic folds and the lower part of the epiglottis. The opening of the larynx is more narrowed, creating an angle between the arytenoids and the aryepiglottic fold. The cuneiforms are also rolled in a bit.
The laryngeal gestures changes to Edge
In Edge the opening of the larynx is even more narrowed, and the cuneiforms are rolled in even more than in Overdrive. This makes it hard to see the vocal folds. The narrowing creates an even more acute angle between the arytenoids and the aryepiglottic fold and also an angle between the aryepiglottic fold and epiglottis. The piriform fossae and area between the back wall (posterior pharyngeal wall) and the larynx becomes very small and is often closed off altogether. The larynx is raised to a higher position (you can see that it gets closer to the camera).
The visual laryngograph waveform appearance
The laryngograph waveform changes from Curbing
Also notice the Curbing laryngograph waveform. It shows a steep onset and a fairly long closure of the vocal folds with a roll off compared to Neutral. The steep onset indicates that the vocal folds are coming together rapidly and the wider shape indicates that the vocal folds stay together for longer, which corresponds nicely with the louder volume often used in Curbing.
The laryngograph waveform changes to Edge
The Edge laryngograph waveform shows a steep onset and a quite long closure of the vocal folds with a gradual roll off. The steep onset indicates that the vocal folds are coming together very rapidly and stay together for longer, so they are closed much longer than they are open. This corresponds nicely with the loud volume often used in Edge.
This video is a male singing on a sustained single note (B2, 250 Hz) on the vowel EH (as in ‘stay’) in Edge and on UH (as in ‘hungry’) in Curbing, alternating back and forth.
This video is a female singing on a sustained single note (Ab4, 420 Hz) on the vowel A (as in ‘and’) in Edge and I (as in ‘sit’) in Curbing, alternating back and forth.
These videos are from the endoscopy study performed by Julian McGlashan and Cathrine Sadolin at CVI in Copenhagen in June 2007. This study has not yet been presented.