Friday, January 22, 2010
By Linda Cole
Dogs and cats and are in a special category when it comes to hearing, or not hearing, their human companions. They can be nowhere in sight, yet never miss the careful opening of a bag of potato chips or cookies. But just try and get their attention when they are in the same room with us – it's like talking to the wall! Cats definitely have selective hearing when it comes to us, but a quiet mouse sneaking up on a missed piece of cat food on the kitchen floor can be heard loud and clear. Their sense of hearing is phenomenal; so it would seem that most dogs and cats only hear us when they want to.
Cat ears are amazing little radar antennas that have the ability to focus in on two different sounds inches apart from each other three feet away. They can distinguish these sounds so precisely and hone in on where the exact sound is coming from that a cat can tell if you are getting into a cupboard that has no food in it versus the one where you keep her favorite treats. They can detect the size of prey and the distance of a sound in just six one hundredth of a second, and can hear five times farther than we can hear.
Cats hear higher frequencies than dogs or humans. Because of that, a woman's voice can be more soothing to a cat, especially if it's upset. Our sense of hearing is in a range of 20 hertz up to 20 kilohertz, but dogs hear up to 40 kilohertz and a cat's hearing jumps into the higher pitched range of 60 kilohertz. However, a cat's range starts at 30 hertz which means they probably don't hear lower tones as well as we do, and that could be why cats don't always respond to a man with a deep voice. Since mice have a tiny high pitched squeak, it's bad news for any wayward mouse in a cat's domain.
Because of the upright and erect shape of their ears, cats can hear with amazing accuracy. Thirty different muscles allow them to rotate their ears 180 degrees independently of each other which helps them focus in on any interesting sounds they hear. These sounds are then funneled down through their ears and picked up by extremely sensitive hairs located in the base of the ear. From there, the sound is transmitted to the cat's brain via the auditory nerve. Even though they are experts at selective hearing, a cat does hear extremely well and knows exactly what is going on in his world.
Dogs can hear with the same kind of accuracy as cats, and their ears also rotate to pinpoint the exact location of where a sound is coming from in less than a second. They can quickly decipher pertinent information to determine if they need to be on alert. If it's a sound coming from another animal, the dog can even determine the height of the animal and know if it's prey or predator.
A dog with floppy ears can't hear as well as those with ears standing erect. Like cats, dogs hear and pick up on our tone of voice as well as the pitch in our voice much better than we realize. As they listen to what we say, they are able to distinguish what we mean by our pitch and tone more than by our words. If we are trying to train a dog, his response is determined by how well we convey a command to him. A sharper tone will get his attention and if you are training a puppy, using a whistle or an abrupt noise will tell him to pay attention to you.
Dogs can move their ears independently too, and have 15 muscles that help them locate and pick up sounds. We can pick up a sound 100 yards away, but a dog can hear a sound that's a quarter of a mile away. Dogs have a unique ability to actually close off their inner ear so they can weed out distracting noises and focus only on the sound they are interested in. I guess that's what they must be doing when they ignore us. And the next time they refuse to go outside in the rain, it might not be because they don't want to get wet, but because the falling rain may actually be hurting their sensitive ears.
Since dogs and cats can hear so well, sirens, loud music and raised voices are annoying to them. We will get their attention better with a softer voice. It's also important to pay close attention to their ears to make sure they are not infected with ear mites or other bacterial or yeast infections that can cause permanent hearing loss if left untreated.
Read more articles by Linda Cole