How Exceptional Is the Ear?

Studies of hearing often conclude that the ear is "remarkable" or that its performance is "exceptional." Some common examples include the following:  the ears of mammals are encased in the hardest bone in the body;  the ear contains the most vascularized tissue in body;  the ear has the highest resting potential in the body;  ears have a unique "fingerprint";  the ear can detect signals below the thermal noise floor; and  the ear is highly nonlinear (or highly linear, depending upon who you ask). Some claims hold up to further scrutiny, while others do not. Additionally, several claims hold for animals in one taxon, while others are shared across taxa. Most frequently, our sense of wonder results from the differences between ears as products of natural selection (over eons) and artificial systems as products of engineering design. Our goal in analyzing claims of remarkable or exceptional performance is to deepen our appreciation of these differences.