Here you see the videoclips of Overdrive. 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.
In the video example below notice the loud, shout-like character of the sound and the visual appearance and waveform of Overdrive.
In Overdrive the front and the back of the laryngeal opening approach each other, making the opening of the larynx much more narrowed and creating a sharper angle between the arytenoids and the aryepiglottic fold, and also a sharp angle between the aryepiglottic fold and epiglottis. The cuneiforms are rolled in even more.
The laryngograph waveform in Overdrive shows a steep onset and a fairly long closure of the vocal folds and sometimes a roll off with a little knee. The steep onset indicates that the vocal folds are coming together very rapidly and stay together for longer, so they are more closed than open during the vibratory cycle, which corresponds nicely with the loud volume often used in Overdrive.
Sustained single notes in Overdrive
The first video is a male singing on a sustained single note (C3, 260 Hz) on the vowel EH (as in ‘stay’) in Overdrive.
This video is a female singing on a sustained single note (Bb4, 480 Hz) on the vowel EH (as in ‘stay’) in Overdrive.
Song in Overdrive
This video is a male singing the first four bars of “Somewhere over the rainbow” in Overdrive.
This video is a female singing the first four bars of “Somewhere over the rainbow” in Overdrive.
Glissando in Overdrive
This video is a male singing a glissando from low pitch to high pitch returning to low pitch again on the vowel EH in Overdrive. Notice that the waveform stays the same through the Overdrive pitches – it just gets narrower as the pitch increases.
This video is a female singing a glissando from low pitch to high pitch returning to low pitch again on the vowel EH vowel, in Overdrive. Notice that the shape of the waveform stays the same through the Overdrive pitches – it just gets narrower as the pitch increases.
This information comes from a study Visual Vocal Mode Test Study on video, with the title ‘Laryngeal gestures and Laryngograph data associated with the four vocal modes as described in the Complete Vocal Technique method of singing teaching.’ This study has not yet been presented.