It comes from the coleoid
Naked mole rats are nearly deaf because their ears can't amplify sound. Naked mole rats have poor hearing because, unlike other mammals, they have abnormal outer hair cells that can't amplify sound. The animals could be used to model human deafness and help develop treatments.
Deafness—the absence of perception of sound—and reduced hearing are common in dogs and cats, and to a lesser extent in other species. Deafness can be hereditary or acquired, congenital or later onset, and sensorineural or conductive.
There are various animals which do not have ears such as ants, snakes, etc. Since they do no have well developed ears, they depend more on their other senses. Animals like snakes sense vibrations around them to hear. While ants use their antennae to sense things around them.
#8: Snakes are deaf
Although they lack eardrums, snakes possess inner ears which are able to pick up not only ground-borne vibrations but low frequency airborne sounds. They do have difficulty with sounds at a higher pitch.
“Surprisingly, we found that they also possess an acute sense of hearing,” he said. “They can hear sounds at distances much farther away than previously thought, even though they lack ears with the eardrums typical of most animals with long-distance hearing.”
Today there's proof, at least for the octopus and squid, that they can indeed hear. To register sound, an octopus uses a sac-like structure called a stratocyst. The stratocyst contains a mineralized mass and sensitive hairs that allow detection of sounds of certain frequencies.
Some squids have been shown to detect sound using their statocysts, but, in general, cephalopods are deaf.
Spiders don't have ears like we do, and many have poor eyesight. But they can sense vibrations, like those that happen when an unlucky insect touches their webs. And instead of eardrums, spiders hear using tiny, sensitive hairs that move in response to sounds.
Some dogs lose their hearing as a result of chronic ear infections. Still others may suffer a traumatic injury to the ear, resulting in hearing loss. Finally, some dogs are born deaf because of a genetic defect; this is called congenital deafness.
Born Blind
Another one is the star-nosed mole, the fastest-eating mammal in the world, who uses touch as their main sensory organ. The olm, the blind cave salamander that looks like a baby dragon, is another naturally blind animal, which can yet perceive light through its hidden eyes and skin.
Our findings show that, despite common assumptions, it is indeed possible for bats to exhibit extensive cochlear damage and deafness.
Butterfly hearing is unusually sensitive to low pitch sounds compared to other insects with similar ears.
At first glance, fish don't appear to have ears, but that doesn't mean they can't hear. While there are usually no openings on a fish's head for sound to enter, they do have inner ears that pick-up sound through their body.
By studying how birds regrow damaged inner ear cells to fix hearing loss, scientists hope to learn how to cure deafness in humans. For decades now, scientists studying hearing loss have been trying to figure out how to make humans more like birds.
Like humans, dolphins tend to lose their high-pitch hearing first, and males tend to go deaf more often than females, Houser told LiveScience. Some dolphins are also born with impaired hearing; certain drugs used to treat the animals' other health problems can also cause hearing loss.
For example, because octopus or squid do not possess gas-filled chambers within their bodies, they cannot amplify sounds, limiting their hearing ability.
Thus deafness is strongly linked to the white coat colour and blue eye colour, but not all white cats or white cats with blue eyes are necessarily deaf. The variable penetrance of deafness and eye colour may be caused by interplay with other genes and/or environmental factors.
Hearing. Elephants have good hearing, detecting sounds as low as 14 to 16 hz (human low range: 20 hz) and as high as 12,000 hz (human high range: 20,000). Elephants frequently use infrasonic sounds, which are sounds emitted below the human hearing range, in long-distance communication.
Octopuses have demonstrated intelligence in a number of ways, says Jon. 'In experiments they've solved mazes and completed tricky tasks to get food rewards. They're also adept at getting themselves in and out of containers.'
Cirrothauma murrayi, the blind cirrate octopus, is a nearly blind octopus whose eyes can sense light, but not form images. It has been found worldwide, usually 1,500 to 4,500 metres (4,900 to 14,800 ft) beneath the ocean's surface.
They “hear” via vibrations. Their eyes are on short stalks that look like antennae (which arachnids don't have); their eyesight is poor. The senses of taste, touch and smell are incorporated in the longer, second pair of their four pairs of legs.
Most people do not realize that most modern insects are also completely deaf. Out of the 30 major insect orders, only nine contain species that are capable of hearing. Amazingly, hearing has evolved more than once in some orders. For instance, the hearing mechanisms in butterflies and moths have evolved six times.
They are also invertebrates (animals without a backbone), which means they have no bones or cartilage – which is what forms ears as we know them. Therefore, all crustaceans lack ears similar to human beings. Instead, crabs are equipped with tiny microscopic hairs covering their shells.