of persuading". We use the expression "to tweak (or pull) someone's ears" to mean "inflict a punishment"." The pinnae have an effect on facial appearance. In Western societies, protruding ears (present in about 5% of ethnic Europeans) have been considered unattractive, particularly if asymmetric. The first surgery to reduce the projection of prominent ears was published in the medical literature by Ernst Dieffenbach in 1845, and the first case report in 1881. Pointy ears are a characteristic of some creatures in folklore such as the French croquemitaine, Brazilian curupira or Japanese earth spider. It has been a feature of characters on art as old as that of Ancient Greece and medieval Europe. Pointy ears are a common characteristic of many creatures in the fantasy genre, including elves, faeries, pixies, hobbits, or orcs. They are a characteristic of creatures in the horror genre, such as vampires. Pointy ears are also found in the science fiction genre; for example among the Vulcan and Romulan races of the Star Trek universe and the Nightcrawler character from the X-Men universe. Georg von Békésy was a Hungarian biophysicist born in Budapest, Hungary. In 1961, he was awarded the Nobel Prize in Physiology or Medicine for his research on the function of the cochlea in the mammalian hearing organ. The Vacanti mouse was a laboratory mouse that had what looked like a human ear grown on its back. The "ear" was actually an ear-shaped cartilage structure grown by seeding cow cartilage cells into a biodegradable ear-shaped mold and then implanted under the skin of the mouse; then the cartilage naturally grew by itself. It was developed as an alternative to ear repair or grafting procedures and the results met with much publicity and controversy in 1997. Other animals The pinna helps direct sound through the ear canal to the eardrum. The complex geometry of ridges on the inner surface of some mammalian ears helps to sharply focus sounds produced by prey, using echolocation signals. These ridges can be regarded as the acoustic equivalent of a fresnel lens, and may be seen in a wide range of animals, including the bat, aye-aye, lesser galago, bat-eared fox, mouse lemur and others. Some large primates such as gorillas and orang-utans (and also humans) have undeveloped ear muscles that are non-functional vestigial structures, yet are still large enough to be easily identified. An ear muscle that cannot move the ear,