Silent Sounds

Creation is full of sounds. Humans hear many of them, but some sounds are “silent” to us because their pitch is either too low or too high for our ears. That’s OK, because God made our ears just right for our needs.

In fact, God made most creatures’ ears just right for their needs. They hear what they need to hear, and the sounds they don’t need to hear are silent to them.

Want to “hear” about some silent sounds? Read on.

Super-Dog

Dogs can hear sounds that are softer and higher-pitched than humans are able to hear. Have you ever seen a dog suddenly perk up its ears and look around? It’s probably hearing a sound that you can’t hear. If your dog is waiting for you when you come in your front door, it’s probably because the dog can hear you coming even if you think you’re not making noise. That’s why some people have watchdogs.

The Dark, Not-So-Silent Deep

People used to think that the deepest parts of the ocean were dark, silent places. Then scientists developed special equipment. Now they record sounds that we can’t hear and play them back at pitches that we can hear.

Surprise! The oceans are full of sounds. Whale calls are a good example. Whales keep in touch with each other over long distances by talking to one another. We call their sounds “whale songs.”

Humpback whale songs can be 25 minutes long. They’re full of what sounds to us like moans, clicks, whistles, and grunts. Scientists think that these sounds are put together in certain combinations, just like we put words together in certain combinations.

To hear some whale songs, check out this website:   http://www.whalecenter.org/av.htm

Don’t Bug Me

Some of the moths that bats like to eat can hear those bats’ squeaks and clicks. When the moths hear those sounds, they drop to the ground. If they’re flying, they may do barrel rolls and fly in zigzags to get out of range. Some moths even click back. Do you think that confuses the bats?

Ears for You Only

All the crickets that you hear singing on a summer evening are males. Female crickets are silent. There are hundreds of different cricket species. As far as we know, each species has its own distinct song. Humans can’t hear the difference, but female crickets can. Scientists think that maybe female crickets can hear only the males of their own species.

Some cricket songs change pitch when the temperature changes. On a cold evening the songs are lower. Even then, a female cricket responds only to the song of her own species. You could say that her “ears change pitch.” We can’t explain how this works.

Silent Prey

Ruffed grouse are birds that nest on the forest floor. They have a noisy mating ritual. The male grouse “drums” to attract a female. He makes a loud thumping noise by beating his wings on the forest floor.

Some owls eat ruffed grouse when they can catch them. So why doesn’t the drumming of a ruffed grouse attract an owl? It’s because the drumming is silent to owls. They can’t hear sounds that are pitched that low.

Driving You Batty

Bats hunt bugs by sound. They make high-pitched squeaks or clicks and listen to the echoes that bounce off the bugs. In fact, most bats make three different series of squeaks or clicks. The closer they are to their prey, the faster they click or squeak.

Those sounds are too high for human ears to hear. Thank God for that. Bats make a real racket to ears that can hear those sounds. If you lived near bats and could hear them, they’d probably drive you batty when they went out hunting.

You can easily hear bat sounds and other animal sounds on your computer by visiting this website: http://www.naturesongs.com/otheranimals.html.

Your Turn

A cricket “hears” changes in air pressure, not sounds. To test a cricket’s hearing, do this: go outside on a summer night and listen for crickets. Then clap and yell without moving your feet. Did they stop singing? Then walk toward them. Now did they stop? They “heard” you coming because walking toward them causes the air pressure near them to change.

Remember those moths that “hear” bats? You can tell if they live near you. On a warm night, turn on an outside light and let moths flutter to it. Then take a bunch of keys, hold them high and jiggle them. Some moths may drop to the ground. Those are the moths that “hear” bat sounds. Your jingling keys make high-pitched sounds like bats make.

Grumble Rumbles

We know that elephants make loud trumpeting noises. We can hear those. But they also make noises that we can’t hear. Elephants live in family groups that are very important to them. If they’re separated, they keep in touch by making low rumbling sounds. One rumble says, “Hello, I’m here.” Another says, “Help, I’m lost.” Humans can hear some, but not all, of these sounds.

Do you think elephants ever grumble when they rumble?

In Conclusion . . .

You get the idea: we can hear only a small fraction of the sounds that fill the air.

Creation—even the world of sound—is much more complicated than we imagine. Yet God gives each of us what we need to live well and enjoy his world.