Have you every stopped and thought about how amazing the human ear is? Despite the fact that there are only two of them, and that they're theoretically much too close together to be effective, they are able to convey sound information to the brain in such an accurate way that the it can the calculate exactly where that sound came from. Left or right, well that's easy because the sound arrives at one ear before the other, but how about directly above, or below? How about dead center and in front or behind? No problem! Those two odd looking growths on the side of our heads funnel pressure waves down the ear canal into what is essentially a quite primitive mechanism from where the magical signal processing begins.