This diagram shows the two key nerves for voice production: 1) the superior laryngeal nerve (SLN) and 2) the recurrent laryngeal nerve (RLN). Both are branches of the vagus nerve and are found on both the right and left sides of the neck.

This diagram also shows the "long path" of the left recurrent laryngeal nerve (left RLN). After it branches off the vagus nerve, the left RLN loops around the aortic arch in the chest cavity and then courses back into the neck.

This long course makes it at higher risk for injury compared with the shorter course of the right RLN which does not run through the chest cavity.

This diagram can be found in Anatomy and Physiology of Voice Production: Learning About the Voice Mechanism.