Hearing in the animal kingdom
When the United Nations General Assembly originally proclaimed March 3 as World Wildlife Day in 2013, their goal was to celebrate and raise awareness for the world’s wild animals and plants. In celebration of conservation in general, Healthy Hearing thought you’d be interested in a few fun facts about animals’ hearing ability. Awareness on any level is key to protecting our valuable resources, whether it’s our animal friends or the sense of hearing which connects us to the world around us.
Our furry best friends
The theme for UN World Wildlife Day 2018 is big cats, such as the lion, tiger, leopard and jaguar, cheetah, snow leopard, puma and clouded leopard. While these elegant members of the wild use their keen sense of hearing primarily to hunt prey, even the most pampered of domesticated cats have excellent hearing. They can detect an extremely wide range of frequencies, hearing higher-pitched sounds than humans or dogs. While a human ear consists of three muscles and the three tiniest bones in the body, a cat’s ear is controlled by close to three dozen muscles, which allow them to rotate their ears 180 degrees.
By today's standards, most dogs would not be considered wildlife with all the creature comforts lavished upon them by dog lovers, but dogs' sense of hearing is impressive when compared to that of their owners. According to Bark magazine, the frequency range dogs can hear is far greater than that of humans. That's why dogs can hear the ultra high-pitched pulse of the crystal resonator in most alarm clocks and even vibrations emitted by termites inside building walls. Their ears can move independently of one another. If you pay close attention to your best friend, you can gain clues about his mood from the position of his ears.
Birds in the wild rely on their keen sense of hearing to either alert them of danger or, in the case of birds of prey, to find their next meal with amazing precision. Owls, for example, have crooked ears. One ear is located slightly forward than the other, which aids them in pinpointing sounds of their prey. Because they are nocturnal animals, their hearing works in tandem with sharp sight to help them hunt successfully in the dark. During flight, an owl's left ear picks up sounds from below while the right ear hears sounds from above.
Moths and spiders
Consider the lowly moth, an insect that has spent so many centuries evading predators that its hearing has evolved to being the best in the human and animal kingdom. Scientists say some species of moths have hearing 150 times more sensitive than any human. Their ability to hear the highest frequencies (300 kilohertz), helps them escape bats, their main predator, before they are attacked.
You may be surprised and even a little troubled to know that spiders - part of the arachnid family - cannot only see you, they can hear you too. An accidental discovery by researchers at Cornell University led them to delve deeper into how spiders hear and respond to sound. As it turns out, spiders are most sensitive to low-frequency sounds and, by using tiny hairs on their forelegs, could "hear" the researchers clap from 5 meters away.
Although the reptilian auditory system is relatively similar across the species, reptiles don’t all hear the same. Snakes, for example, don’t have an outer ear or eardrum. Instead, a bone in their jaw moves in response to vibrations they detect on the ground and in the air. This movement is transferred to the inner ear, which is sent to the brain to be interpreted.
Lizards, on the other hand, have visible openings with eardrums just below surface of their skin. While they don’t hear as well as humans, they are able to hear better than snakes.
Did you know the human ear evolved from fish gills? That’s what scientists believe. Today of course, human hearing is vastly different from that of a fish. In addition to ear parts inside their heads, fish have lateral lines which run down the side of their body and help them pick up sounds in the water.
Dolphins use echolocation to hear where they are going. By emitting a squeak, the sound bounces off surfaces and back to its lower jaw, providing a sound map of what’s ahead. Their teeth also help with hearing, acting like an antenna to help receive incoming sound. Scientists say dolphins have a hearing range from 20 Hz to 150 kHz, which is seven times better than humans.
The human advantage
Hearing is such an important sense for all members of the animal kingdom, including humans. Even though we may not be able to hear as well as some of our animal friends, we do have some advantages. Thanks to hearing healthcare professionals and advancements in technology, our hearing can be evaluated and treated, helping us hear our best throughout our lifetime.
Preserve your sense of hearing by turning down the volume on the television and other personal electronic devices, protecting your ears from loud noise and having annual checkups with a hearing healthcare professional you trust. If you don’t know where to start, visit Healthy Hearing’s directory of patient reviewed hearing healthcare professionals.