The ear is one of the most complex parts of the face to model. We can make it easier to do though by using the Extrude Edge technique. First create an object plane in the Attributes window. Make the plane to 4 x 10 cm. Set the Width and Height Segments to 1 and the Orientation to Z (Fig.01a). After doing this make the object editable by pressing "C". Use the perspective view to switch between the front and back views. Select the lower and higher edges and extrude them with the Extrude tool. Create new polygons to form the profile of the entire ear (Fig.01b). Use the Bridge tool to close the mesh (Fig.01c). You should end up with something like Fig.01d.
Continue to extrude the edges to create a path for the inside of the ear (Fig.02a). With the Bridge tool, connect the external mesh with the newly created mesh (Fig.02b). By following these steps you should have created the basic shape of the ear (Fig.02c). Remember the number of edges on the inside must match the number on the outside edge.
With the Bridge tool connect the edges between the paths to close all the gaps in the inner ear (Fig.03a). It might help to use the Knife tool (K) by adding cuts to simplify the bridges (Fig.03b - 03c). By doing this you will get the entire closed shape of the ear, including all its loops, which will mean you will get the volumes anatomically correct (Fig.03d).