Sssh. Can you hear something? We can tell the difference between
loud sounds and quiet sounds. You can even tell the difference
between your mum's voice and your teacher's voice. But how do we
Movement of the air - vibrations - are the
basis for all sounds. Different sounds and voices cause different
vibrations in the air. Your ears collect these vibrations and
convert them to nerve signals. These nerve signals are sent to your
brain. Your brain works out what the signals mean - it converts the
signals into sound.
What if we could collect MORE sound waves?
Would we be able to hear even more sounds? Try this and see:
- Roll a large sheet of paper into a cone shape. One end should
be as large as possible. The other end should have a hole about the
size of a penny.
- Sellotape the paper so the cone doesn't unravel.
- Hold the narrow end of the cone to your ear.
Don't put the cone in your ear - your ears are
very delicate and you don't want to damage them!
- Walk around your house - what can you hear? Are the sounds
louder? Can you hear sounds you haven't heard before?
Your homemade hearing aid works in the same way as your ears -
it collects sound waves in the large end of the cone and funnels
them into your ears. Because the cone is bigger than your ears,
more sound waves can enter your ears. You should be able to hear
quiet sounds much more clearly. Try it and see!