Grade 1 → Smaller than normal, but the ear has mostly normal anatomy.

Grade 2 → Part of the ear looks normal, usually the lower half.  The canal may be normal, small or completely closed.

Grade 3 → Just a small remnant of “peanut-shaped” skin and cartilage. There is no canal, which is called aural atresia.

Grade 4 → Complete absence of both the external ear and the ear canal, also called “anotia.”