Auditory nerve
The auditory nerve, or cochlear nerve or acoustic nerve, was one of two parts of the vestibulocochlear nerve, a cranial nerve.

In 2375, The Doctor sang up to a range of 880 hertz in order to check for damage to Chakotay's auditory nerves. This was done after exposure to chaotic space had reactivated a previously suppressed gene that caused, among other symptoms, auditory hallucinations. ()

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Anatomy