Overview
Deafness is often difficult to assess accurately, mainly because cats are not able to tell us when they have trouble hearing. Usually, it is their failure to obey commands or respond to familiar noises that first alert cat owners to a deafness problem.
Compared to humans, cats have a much different range of hearing. Humans can hear sounds in the 20 Hz (low sounds) to 20 kHz (high sounds) range. By comparison, a cat has a range of about 48 Hz to 85 kHz.
Deafness can be hereditary in many breeds. It can also be associated with a genetic predisposition. Cats with white coat color and blue iris genes are predisposed to deafness.
Determining if Your Cat is Deaf
Deafness is difficult to evaluate in cats, especially if only one ear is involved or if there is only partial deafness. Since pets cannot tell us what they hear, the best criterion for confirming whether a cat can hear or not is by its response to sound (i.e. the pet must consciously perceive the sound).
You can determine your cat's ability to hear by making various noises (from quiet to increasingly louder noises) and seeing if your pet reacts. Often, cats will display an involuntary flicking or twitching of the ears (called "Pryor's reflex) in response to a sound. Some veterinary schools have also had some degree of success with objective evaluations of hearing, using electrodiagnostic procedures.
If you suspect that your cat has a hearing problem, consult your veterinarian so that he or she can determine what kind of deafness is involved and what can be done about it.