By the seventh week, the three pairs of hillocks have enlarged differentiated and fused together to start forming the auricle, or outer portion of the ear.

Simultaneously, in the seventh week of development, the auditory tube begins to form out of the tympanic membrane.

Type I: External portion of the ear is small in size; auricle structure is normal Type II: The auricle is in a hook or 'S' shape; external ear is only moderately abnormal.

Type III: Small amount of basic, soft tissue ear structure lacking cartilage; auricle is abnormal in appearance.

Defects affecting the external ear such as the auricle results from malformation or suppression of the auricular hillocks, which are small swellings on the embryonic visceral arches or the beginnings of the external ears; the small swellings are derived from the first and second pharyngeal arches.

Goldenhar syndrome: A rare congenital birth defect that causes abnormalities of facial development.

The defect is capable of affecting tissue, muscle, and the underlying bone structure of the side of the face with the abnormality.

Ablepharon macrostomia syndrome : (AMS) A rare genetic disorder characterized by various physical anomalies which affect the craniofacial area, the skin, the fingers, and the genitals.