Margin swelling (1 of 6)
Breathing position of the vocal cords of a very hoarse actor. Note the margin swelling of both sides. The white material on the left vocal cord (right of photo) is keratin debris emerging from an open cyst. Find the sulcus of the right vocal cord (left of photo) which is more easily seen in the next photo.
Narrow band light (2 of 6)
Further magnified and under narrow band light. The right sulcus is within the dotted outline. Compare now with photo 1.
Open phase, strobe light (3 of 6)
Under strobe light, open phase of vibration at A3 (220 Hz). The full length of the cords participate in vibration.
Closed phase, same pitch (4 of 6)
At the same pitch, the closed phase again includes the full length of the cords.
Segmental vibration (5 of 6)
At the much higher pitch of C5 (523 Hz) a “tin whistle” quality is heard and only the anterior segment (at arrows) is opening for vibration. The posterior opening is static and not oscillating, as seen in the next photo.
Closed phase (6 of 6)
The closed phase of vibration involves only the tiny anterior segment of the vocal cords, at the arrows. The posterior segment is not vibrating and is unchanged.