When the patient inhales and his diaphragm contracts, the pacemaker sends a weak electrical impulse via a second cable to the hypoglossal nerve.
From the sciencedaily.com
The hypoglossal nerve, which passes through the canal, controls the movements of the tongue and its size is said to reflect speech abilities.
From the en.wikipedia.org
Another, the nerve crossover, requires the use of an undamaged nerve-usually the hypoglossal nerve that controls tongue movement-to innervate facial muscles as well.