XFdtd Simulation Of Electric Fields Between Two Headphones

How do the electric fields between two headphones on the body interact in relation to the human head? Does most of the coupling occur due to waves traveling around or through the head? In this example, four scenarios are simulated in XFdtd.

Scenario A: The realistic case: two headphones on an unaltered human head.
Scenario B: The human and freespace are split in half by an infinite sheet made of a perfect electric conductor (PEC).
Scenario C: A PEC plate surrounding the head (i.e., waves must travel through the human to reach the other headphone).
Scenario D: The PEC plate splits the human in half, but freespace surrounds the human (i.e., waves are free to travel around the head).