 |
|
|
Echoes and Sound
by Quaphys.info
Explore the causes of echoes and carry out your own research experiment. This is best enjoyed by ages 10 and under.
Have you heard a rumble, a scream, a whisper, a rustle, a purr, or a slam? We have many different names for all the sounds we hear. It seems like we need to keep coming up with new words to
describe all the new sounds we hear everyday.
Can you tell the difference between a loud sound and a soft sound? Can you tell the difference between a high sound and a low sound? Have you heard nice sounds and some really unpleasant sounds?
All the sounds we hear are caused by the vibrating (moving back and forth) of something.
When you hear the rustle of leaves, it is the wind causing them to move back and forth. Have you heard the roar of a lion? If you have, then you have heard a lion using his vocal chords. They are
located in the back of his throat and when the lion roars, its vocal chords begin to move back and forth.
Strings on musical instruments vibrate to make the sound that you hear, while other instruments use air to vibrate and cause music. In others there maybe a sheet of metal, or skin, that
vibrates.
The air carries these sounds to our ears. If you think of a pond, then imagine sound traveling to your ears like the ripples you see in the water when a rock has been thrown into it. The
difference is that you can see the ripples in the water, but you cannot see the sound waves as they reach your ears.
Sound is capable of traveling through many materials, but it travels faster through some more than it does through the air. If sound waves hit a solid wall, they will bounce off the wall and you
will hear an echo. If you were to blow a trumpet in an area that causes an echo, then each time you blew your trumpet, your ears would hear it twice. The first time you hear it is when you blow
the trumpet and the second time you hear it is when the sound waves have been bounced back to your ears. The sound waves become bent creating the echo.
If you are about a half mile from a solid wall and you blow a trumpet, it will only take about 5 seconds after blowing to hear the echo since it only takes five seconds for sound to travel a
mile. Will it work if you just speak? Of course, you can hear the words you spoke when they return.
There are even some famous echo places in the world. One such place is in Ireland because it has so many mountains with small lakes inside. If you were to blow a trumpet in one of these places,
it may echo a hundred times before dying away.
Experiment:
Why not try to create an echo? You don't have to go to the mountains. All you need is a blank wall (a wall without windows). Don't stand too close to the wall, if you want to hear your echo. If
you stand any closer than about 50 feet, then when you shout, the shout and the echo will seem to be one sound. Sometimes echoes can be irritating and in concert halls, curtains are placed on the
wall to prevent echoes.
|
|
|
Please visit our
affiliate partners that
keeps our site up.
|
|
