Parkinson’s-related voice change (1 of 3)
Larynx of person with severe Parkinson’s disease; breathing position. Note the remarkable atrophy of the vocal cords, manifested in particular by the capacious ventricles (green dotted lines), the margin bowing (arrows), loss of “conus” bulk, and increased visibility of the contours of the vocal processes (blue dotted lines).

Parkinson’s-related voice change (2 of 3)
Phonatory (voicing) position. In addition to the bowing of the vocal cords, especially the left cord (right of image), note the slight scissoring of the left vocal process to overlap the right vocal process, as indicated by the arrows.

Parkinson’s-related voice change (3 of 3)
Cords coming into phonatory position, magnified view. Here can be seen even more clearly that, due to Parkinson’s-related atrophy, the contours of the vocal processes are more visible (blue dotted lines), like an emaciated person’s ribs. Note also that the LCA muscles have contracted slightly before the IA: the “toes” (T’s) of the arytenoid cartilages are in contact before the “heels” (H’s).