As a means of survival in the wild, cat hearing is acute, not just for aiding in a quick escape but to help with hunting. Their hearing range is amazingly superior compared to other mammals.
What Makes A Cat Hear So Well?
A cat’s hearing is able to register sounds on the lower and higher end of the hearing range and amplifies them two to three times the actual frequency. Because the external ear, or pinna, is shaped like a cone the sound wave funnels into the ear canal and magnifies the sound. The outer ear has approximately 30 muscle groups which allow the cat to move the pinna up to 180 degrees independently, enabling the cat to lock onto the direction of the sound. Interestingly, with these factors in place a cat can pinpoint sounds that are as small as three inches apart from only three feet away. This enlightens us as to why cats make such good hunters. Unlike many mammals that hunt, cats do not expend a great deal of energy on running for their prey but simply stalk it.
How The Ear Works
The sound funnels into the pinna and travels into the ear canal where it reaches the ear drum. The ear drum in turn vibrates and causes a series of three small bones to move which then pushes on a small membrane called the cochlea. The cochlea is filled with fluid that makes waves from the nudges received. Also inside the cochlea are fine hairs, which respond to the movement of the fluid. These hairs move, depending on the sound being made, and send a signal to the brain. This tells the cat what the sound is being made by and where to locate it.
The Hearing Range
Cats are able to hear even the most insignificant difference in sounds, as little as 1/10 of a difference can be detected by their superior range of hearing. Being able to make that distinction is what allows a cat to decide on which prey to pursue. The hearing range of a cat is one of the broadest found in mammals even though the lower range is shared with many other species. There are several opinions on the lower range limit but in general the frequency for the lower range seems to be approximately 20 to 30 kHz, which is about the same as humans. The sense of hearing is much more evolved on the higher end, ranging as high as 64 kHz. That means not only is their hearing range 1.6 octaves higher than that of a human but even a full octave higher of that for canines. Humans are most sensitive to sounds in the 3000 Hz range where cats are more sensitive to sounds falling in the 8000 Hz range.
Their hearing level is so keen (close to four times greater than a human) they can actually hear electrical current. As with most animals, cats can suffer from hearing loss as they age; the frequency level drops from aging, or even from over exposure to loud noises.