Why do animals’ ears look different from yours? What would life be like if your ears were shaped differently? Make new ears for yourself and find out.
- Stapler and staples
- A variety of construction materials including (but not limited to) construction paper, cardboard, plastic pieces, or Styrofoam, plastic containers and trays (clean yogurt cups and meat trays, for starters), craft sticks, and so on
- Pictures of animals’ ears
Use your materials to fashion new outer ears, or pinnae, for yourself. Look at pictures of animal ears if you need ideas or inspiration. (Be careful not to cover the opening to your own ear when you make these new ear shapes—you want to collect sound in new ways, not block it!)
Compare your normal hearing with what you can hear when you wear the new ears you’ve made. What happens when you wear tall, thin ears like those on a horse? What happens when you wear ears with flaps over them, like a basset hound’s? Can you invent a shape you don’t see in nature?
Trade the ears you made with others to see how differently shaped ears collect sound. What are the advantages and disadvantages of changing the shape of your ear? Does one design work better than the others? Do things sound different if you’re wearing two different types of ears?
Look at the animal pictures again. You might have some clues now about why each of these animals has the kinds of ears they do.
You’ll probably find that the ear designs that amplify sounds the best will be funnel shaped and have large pinnae, or outer ear flaps. The pinnae of human ears (and most animal ears) act like funnels, collecting and directing sound into the inner ear, so our brains can detect and analyze what we hear.
Ears can also tell us about an animal’s lifestyle. Some animals (such as dogs, elephants, and whales, for instance) can hear frequencies too high or low for us to hear. In some owls, one ear is set slightly higher than the other. This allows them to pinpoint the position of prey while in flight, assessing location in an up-and-down plane, in addition to left and right.
Animals that have very large ears (jackrabbits and foxes, for example), can generally hear very well, or at a great distance. Big ears can help animals locate prey, avoid predators, and find others of their kind.
Large ears can also provide extra surface area to radiate heat away from the body. In animals that cannot sweat as we do, having an expanse of blood vessels close to the skin’s surface allows excess body heat to escape. In fact, ear shape is one way you can tell African elephants from Indian elephants: Elephants adapted to live in the hot African climate have bigger ears than Indian elephants have.
You might notice that your “designer ears” magnify a lot of background noise. Big pinnae funnel every sound to the ear—often a problem for people who wear hearing aids.