Hearing

Sound is really a vibration.There are sound waves in the air- which
we dont see ofcourse- that travel to our ears and get translated by
the brain. They work in a very similar way as waves- it ripples, like
when you throw a pebble into water and that spot moves causing the
water right near it to move as well, and the water around that, too.
So when something vibrates, it causes the air around it to move (adn
the air right next to the moved air to move in response as well)=
sound waves.
In this set of pictures, you see a few snapshots of us performing
different experiments to help us understand this:
We placed a napkin with salt over the cd player's speakers. When no
music was playing, the salt lay still.... but when the music played
the salt danced!!!! And if the music was louder, the salt danced
faster adn v.v.
After seeing this we were able to understand why we feel movement in
our throat when we talk. Because the sounds we hear when we talk are
really the air passing through our vocal cords and making them move.
We also tried seeing what happens when we whisper into someone's ear
through a tube. They were able to hear us better because the sounds
waves were trapped in a smaller space.
We also placed a napkin over the whole at the bottom of the tube and
then spoke into it. we were able to feel the vibrations. We noticed
that you can "feel" the person talking.