Annette Ikeda, age 10, of Costa Mesa, Calif., for her question:
DO DOGS HEAR BETTER THAN PEOPLE?
Your own dear dog may be a true breed or an ordinary pooch with a mixture of ancestors. In any case, you can be sure that he hears softer sounds from farther away than you can hear. He also hears a lot of super high notes that your ears cannot catch at all. What's more, he has a keener nose for detecting smells. However, your bright eyes are sharper than his and he cannot see colors at all.
It is a nice idea to train your dog to come when you blow a silent whistle. Actually, this special dog whistle is not really silent. The`sound it makes just cannot be heard by human ears. It cannot bother the human neighbors but it is heard by the neighborhood dogs. This is because our ears hear notes that go only so high and a dog can hear notes that are higher.
Maybe you can hear human voices from 25 yards down the street. But your dog can hear sounds of this sort from 10 times farther away. His ears are much keener than ours, and he also hears sounds we never hear. And, as a rule, a smallish dog has sharper ears than the larger types.
Most of the sounds we hear are caused by vibrations jogging through the air. High notes vibrate faster than low notes. For example, the lowest notes we hear vibrate at about 20 times per second, the highest at about 20,000 times per second. The range of normal human hearing includes about 10 octaves.
Our ears are deaf to the dog whistle because its sounds vibrate faster than 20,000 per second. A dog can hear it because his keener ears can hear sound vibrations as. high as 30,000 times per second. What's more, we can train the smart fellow to come when he hears his own personal whistle. Training starts when you blow the whistle and serve his dinner or give him a friendly caress. He soon catches on and comes running for his reward when he hears his whistle from afar.
A dog's world is full of sounds we cannot hear and smells we cannot smell. Though he sees quite well, he prefers to depend upon sounds and scents to bring him news of what goes on around him. A trained dog can scent his master in a huge crowd of people, track a lost person through the wilderness or sniff out a small sack of drugs in a whole warehouse full of crates.