Wordnet 3.0
ADJECTIVE (2)
1. 
 of or pertaining to hearing or the ear; 
- Example: "an animal with a very sensitive aural apparatus"2. 
 relating to or characterized by an aura; 
- Example: "various aural effects that precede a migraine headache"
The Collaborative International Dictionary of English v.0.48:
Aural \Au"ral\, a. [L. aura air.]
   Of or pertaining to the air, or to an aura.
   [1913 Webster]
The Collaborative International Dictionary of English v.0.48:
Aural \Au"ral\, a. [L. auris ear.]
   Of or pertaining to the ear; as, aural medicine and surgery.
   [1913 Webster]
WordNet (r) 3.0 (2006):
aural
    adj 1: of or pertaining to hearing or the ear; "an animal with a
           very sensitive aural apparatus"
    2: relating to or characterized by an aura; "various aural
       effects that precede a migraine headache"