The Collaborative International Dictionary of English v.0.48:

Auditory \Au"di*to*ry\, a. [L. auditorius.]
   Of or pertaining to hearing, or to the sense or organs of
   hearing; as, the auditory nerve. See Ear.
   [1913 Webster]

   Auditory canal (Anat.), the tube from the auditory meatus
      or opening of the ear to the tympanic membrane.
      [1913 Webster]

WordNet (r) 3.0 (2006):

auditory canal
    n 1: either of the passages in the outer ear from the auricle to
         the tympanic membrane [syn: auditory meatus, acoustic
         meatus, ear canal, auditory canal, external auditory
         canal]