Why dogs can hear sounds people can't?

When you blow a whistle, your dog perks its ears and comes running. If you have a Galton whistle or silent whistle, your dog can hear it.

"Silent" sounds--those you can't hear-- are all around you all the time. Dogs can hear more of these sounds than you can. Your dog can pick up sounds that are too high for your ears to hear. It can also hear fainter sounds than you can.

Sound waves travel at different rates. The more vibrations per second, the higher the pitch of the sound. A bird's song, sets up faster vibrations than a bass fiddle does.

The ear is a sound receiver, when vibrating waves strike your ear (or your dog's ear), small bones begin to vibrate. One bone starts fluid vibrating in a part of the ear called the cochlea. There, cells change the vibrations to nerve impulses that travel to the brain. The human ear can pick up sound waves that vibrate between 20 and 20,000 times a second. A dog's ear has a more sensitive cochlea, it can detect as many as 50,000 vibrations a second.

In addition to hearing higher and fainter sounds than humans do, dogs can tell the difference between very similar sounds. If you trained your dog to come at the sound of a silent whistle, or one you can hear, don't change it. Your sharp eared pet might pay no attention to a new sound.