If dogs could talk, they’d almost certainly proclaim hearing as their second most important sense. Smell being their first most important sense. Because people are so verbally oriented, we expect our canine counter parts to listen a lot, and they’re remarkably willing. If you watch even a sleeping dog, you’ll notice their ears swivel, reacting to sound.
Humans and canines share many of the same anatomical characteristics of the ear. The difference is the outermost section. Our ears are very much plastered to our heads, and the ability to wiggle them even a tiny bit is considered amazing. A dogs ears are made to collect sound. Some may be floppy or erect, but they are far superior to ours. A dogs ears can move independently from eachother, making it easier for them to discriminate and pick up sounds all around them.
The external auditory canal leads down from the base of the outer ear called the pinna. It then makes a nearly right angle turn inward to the eardrum. Vibrations reaching the eardrum pass through the tympanic cavity via three tiny bones known collectively as the auditory ossicles. This section comprises the middle ear.
The inner ear is responisble for turning vibrations into nerve impulses. Vibrations pass through a snail-shaped tubular structure called the cochlea. This converts the vibrations into nerve impulses and then sends them along the auditory nerve to the brain for processing.
Ok, so now you know how the canine ear hears.. now lets talk about what it hears. Sound is measured in vibrations, or cycles, per second, termed either cps or hertz. It is accepted that humans can hear 20 to 20,000 hertz, with the optimum range between 1,000 and 4,000 hertz. Agreement among scientists about canine hearing, however, differs. While it is generally acknowledged that dogs hear somewhat less in the ultra-low range and considerably more in the high-frequency range, actual numbers vary widely. Most experts cite upper limits of 35,000 to even 100,000 hertz! It is said that Pavlov (famous for making a dog salivate by ringing a bell) demonstrated that dogs react to sound at 75,000 hertz. Whatever the upper number may be, it is far greater than ours!
So having a high hearing range means that dogs are flooded with sounds. One impressive talent dogs seem to have is the ability to screen incoming sounds. If you’ve watched your dog sleeping soundly suddenly spring into alert at the sound of the can opener or the crinkling sound of a bag after sleeping through loud music, a blasting t.v., or the family wrestling match, you’ve witnessed sound screening at work.
Dogs also have the ability to locate the exact point where the sound is coming from. Which isn’t really suprising if you think about it. A wolf or wild dog hearing the sound of a rabbit, but misjudging it’s location by a few yards wouldn’t make for a well fed dog.
Probably the most intiguing element of canine hearing is the mobile ear flap. Dogs can foucus and capture sounds with each ear independently. Police have learned to watch their dogs’ ears for clues to a situation. Both ears focused in the same direction as the muzzle indicates a suspect in that direction, while one ear flicking repeatedly away from the forward direction to some other consistent position likely indicates a second person in the area.
So now you know how dogs hear, and what they can hear. If you’d like to test your dogs’ hearing try putting your dog in another room with someone else and have that person distract them by talking to them. Then go into the kitchen and crinkle a bag of chips or of their favorite treats and watch them come running! Another way to test your dogs’ hearing is to wisper a command to them while they are just laying around, even if they don’t obey the command, you’ll more than likely see their ears move in your direction!
The following are some ways to recongnize hearing problems in your dog:
Pups are born deaf. As a matter of fact their ears don’t open until they are 10 to 14 days. If your pup is not responding to sound after that time, it may be congenitally deaf. This problem is often associated with white coat coloring, and occurs more in Dalmations, Bull Terriers, Jack Russells, and Australian Shepherds/Cattle dogs.
Any dog that does not seem responsive to sound, no matter it’s breed or age, should be checked for effective hearing. You can preform a very rough test by standing behind your dog and clapping your hands loudly, but your veterinary neurologist can preform an actual hearing test called a BAER, or brainstem auditory evoked response, test. This test simply measures the degree of hearing loss in each ear.
Since the middle ear is long and curves at a near right angle, it is important to clean your dogs ears regularly. The middle ear is a great place for bacteria and yeast to grow, especially if your dogs ears are floppy. Bacteria and yeast can cause painful ear infections and block, even destroy in worst cases, your dogs hearing.
So remember, if you call your dog to you and he/she doesn’t respond, have him or her checked out by a vet. If everything is ok with your dogs ears, he/she may just have changed their name for the day!