This video is a male singing on a sustained single note (C#4) on the vowel EE (as in ‘see’) in Neutral with air and then adding in distortion – and Neutral without air and then adding in distortion – then Curbing on the vowel I (as in ‘sit’) and then adding in distortion – then Overdrive on the vowel EH (as in ‘stay’) and then adding in distortion – then Edge on the vowel A (as in ‘and’) and then adding in distortion.
Notice that the false folds (above the vocal folds) are vibrating against each other creating the distorted sound while the vocal folds are vibrating freely underneath creating the tone.
Also notice that the waveform of the vocal mode is maintained during the distortion. This indicates that the vibrations of the vocal folds are unhindered and unaffected by the distortion. So the vocal folds are vibrating freely under the distortion. This makes sense because the we know that the distortion is taking place at the 2nd level (the level of the false folds) and not on the 1st level (the level of the vocal folds).