HEARING
Sound
is sensed by the ears. There are a lot of noises in the
world, especially if you're living in a city. Our eardrums
pick up these noises and try to make sense of them in the
brain. We can often hear things that aren't there or not
hear things that are there. Have you ever wondered whether
there would be a sound if a tree fell in a forest with no
one around to hear it? A lot of people have wondered about
this. Some claim that if there were no eardrums to pick
up the sound waves, the falling tree wouldn't make a sound.
But, how could we actually test such a claim?
EXPERIMENT
Where
is the Sound Coming From?
Put
a blindfold on and sit on a chair in the middle of a room.
You need three friends to gather sound makers that are the
same, such as spoons. One will sound a set of spoons above
your head, another will do the same in front of you, and
the other will sound his set of spoons behind you. Try to
have all sounds made at equal distance to the ear. If the
sounds are made at the same time, you shouldn't be able
to figure out where the sound is actually coming from. Be
sure not to move your head during the experiment.
Test
Your Hearing Abilities:
Make
a tape recording of a person talking but change the volume
while you're doing it. Start with very, very quietly and
slowly increase to very, very loud. Have different people
listen to the same tape and each explain what they heard.
Now play the tape back at "normal" volume. How
did you do? Were there certain times during the tape recording
that it was especially difficult to hear?
You
can modify this experiment a bit and have someone make a
variety of noises in the background, where they can't be
seen. Have everyone write down what they hear and compare
the results with the actual sounds used. Here are a few
examples to use:
| RUNNING
WATER |
POT
CLANKING |
| BLENDER |
POPCORN
POPPING |
| STATIC
FROM THE TV |
SPOON
MUSIC |
| DOOR
SLAMMING |
DIFFERENT
INSTRUMENTS |
Also
think of other things that each noise may sound like and
guess some of the common mistakes that can be made by all
of us, when hearing certain sounds.
EXPERIMENT
Have
you ever held a seashell up to your ear and heard the ocean?
You can even make this sound with a jar! Noise from our
environment, including the noise your ear is making by brushing
up against the jar, is what's making the sound. The sound
is then reinforced by the vibration of air within the jar.
This sound, called resonance, sounds a lot like the ocean.
