Because of its complexity the ear is modeled as a separate object and attached to the head later.
In this tutorial the goal is to create as simple as possible but still moderately realistic 3D model of a head. Because of this the ear has been simplified a little and therefore is not completely realistic. If you would like to create fully realistic 3D model of an ear I recommend reading Krishnamurti Martins Costa's tutorial about modeling realistic 3D ear. From www.3dtotal.com site you find also many other high quality tutorials about 3D modeling of a character.
Picture 1. Start the modeling of the ear by creating polygons according to the picture.
Hide the 3D model of the head and create a new plane object in the Right view. Change the width and height segments in the plane object to one. Turn the plane object into Editable Poly and create new polygons by copying edges according to picture 1.
Remember to use Editable Poly's Target Weld function to weld polygons together when necessary.
Picture 2. Create new polygons inside of the ear.
Create 4 new polygons by copying edges and place them according to picture 2. Remember to check the location and orientation of the polygons both in the Right and Front views.
Picture 3. Create new polygons according to the picture.
Select 8 edges and create 8 new polygons by copying the selected edges inwards according to picture 3.
Picture 4. Create new polygons according to the picture.
Create 8 new polygons to the deepest part of the ear according to picture 4. Notice that all 8 polygons are four sided (quads) even though some of them might look like three sided.
Picture 5. New polygons inside the ear.
Select 11 edges and create new polygons by copying selected edges inwards according to picture 5. Notice that two vertices must be welded by using Editable Poly's Target Weld in the location marked with yellow circle.