Cats are sometimes misunderstood creatures. You may find them standing in a corner looking at the wall, acting like they are chasing something that isn't there, or running around the house like they see a ghost. The truth is, cats don't have ESP (at least not that we know of!) but their senses are quite different from our own. A cat's hearing, for example, amplifies sounds and their ear swivels to give them a clear auditory picture of things that humans just can't hear.
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How cats' hearing works
The shape and position of a cat's ears allow it to hear extraordinarily well. The cat's outer ear is large, upright, and cone-shaped. The shape of the cat's outer ear, called the pinna, captures sound waves and funnels them through the ear canal to the eardrum. The pinna is controlled by 30 muscles, which allow it to rotate 180 degrees. By contrast, dogs have about 18 muscles that control their pinna.
Cats can control each ear's pinnas independently, so they can swivel each ear to pinpoint the source of a noise. The deeper and more tapered shape of a cat's ear canal funnels sound deeper into the ear more effectively. The cat's inner ear has three tiny bones, the the hammer, anvil, and stirrup, which function the same way a human ear does.
What can cats hear?
The cat's ear can amplify sound waves two or three times for frequencies between 2,000 and 6,000 cycles per second, also known as Hertz (Hz). The normal hearing frequency range for humans is 20 to 20,000 hertz. In decibels, humans can hear a normal audible range of 0 to 180 dB, although anything over 85 dB is considered loud and potentially damaging.
Humans and cats both begin their audible range of hearing at around 20 Hz, but cats can hear frequencies much higher than we can, and much higher than dogs can as well. The journal Hearing Research says the hearing range of the cat for sounds of 70 dB SPL (sound pressure level) extends from 48 Hz to 85,000 Hz. By comparison, the AKC says that dogs can hear from up to 67,000 hertz. Us mere mortal humans can detect sounds up to 20,000 hertz.
An often cited older research study by Louisiana State University says cats are capable of hearing much higher-pitched sounds of up to 1.6 octaves above the human range, and one octave above what canines can hear. the range of a canine. Animal Planet says a healthy cat can hear a noise four or five times farther away than humans can. Not only that, they are such skilled hunters that if a cat three feet away from the origin of a sound, it can pinpoint the location of that sound to within a few inches in a mere six one-hundredths of a second.
Deafness and blindness in white cats
There is a common belief that white cats are born either blind or deaf, or both The truth is, white cats have no higher incidence of hereditary blindness than cats of other colors. However, there is a chance that blue-eyed, white cats are more prone to deafness. For cats with two blue eyes, the Cornell Feline Health Center says that 65 to 85 percent of all-white cats with two blue eyes are deaf.
Only 17 to 22 percent of white cats with non-blue eyes are born deaf. For cats with one blue eye, that percentage rises up to 40 percent. If a cat has one blue eye, they will always be deaf on the same side as the blue eye.
Why are white cats with blue eyes deaf? Genetics is the culprit. The gene responsible for white coat color is a dominant gene called W. this gene is not only responsible for the white coat color but has more than one effect — that of blue eyes and deafness as well. Since it is a dominant gene, all cats with the gene will have a white coat, which also strongly links the gene to the blue eye color and a cat's sense of hearing as well, but not all white cats or white cats with blue eyes are deaf. genes and/or environmental factors.
Still, it's common enough that responsible breeders and owners should check their white cats for deafness through a simple test called the BAER testing — brainstem auditory evoked response. If you have a cat with deafness, it will need extra care and attention to protect it from speeding cars and predators.
- Merck Veterinary Manual: Ear Structure and Function in Cats
- Hidden Hearing: Things You Didn’t Know About Cats and Their Hearing
- Psychology Today: How Dogs Hear and Speak With the World Around Them
- Amplifon: The Normal Hearing Range
- Hearing Research: Hearing Range of the Domestic Cat
- AKC: Sounds Only Dogs Can Hear
- Cornell Feline Health Center: Ask Elizabeth: White Cats and Blindness/Deafness
- International Cat Care: Inherited Deafness in White Cats
- Louisiana State University: How Well Do Dogs and Other Animals Hear?
- Animal Planet: Cat Ears & Hearing