The most critical part of the Outer Ear is the External Auditory Meatus.
But then try to imagine Tom Cruise with rabbit or donkey ears and the spell might be diminished a bit (my wife denies this, of course). As it is, the Pinna is suitable for piercing purposes, hanging earrings and perching glasses on. Some boxers also like to bite it.
Somewhat centered in the Pinna is the ear canal. That is what we called it in CD 261; but this a 300 level course so it is now referred to as the External Auditory Meatus.
There is a quaint line I once heard in a Humphrey Bogart movie (I think) that goes like, "Breath in my External Auditory Meatus one more time and you'll get five extra ossicles in yours." And then again it may have been a Bugs Bunny cartoon.