REDIRECTING RIPPLES

INTRODUCTION

Sound energy travels in all directions like the ripples in a puddle. If we use a cone, we can catch more of this energy and bring it to one place. If we use a hollow hose, the sound will travel through it around corners and bends.

WHAT YOU NEED

WHAT YOU DO

1. Stick the neck of the funnel into one end of the hose. Twist it in tightly so it doesn't fall out. You have just made a stethoscope like the one your doctor uses.

2. Have your partner hold the large end of the funnel tightly against their chest. Put the other end of the hose near your ear. Can you hear your partner's heartbeat? _____________________________

3. Let your partner listen to their own heart. This means that the hose has to bend but the sound still follows the hose.

4. After you've both had a chance to listen to your own and each other's hearts, pull the funnel out of the hose. Try to listen to your partner's heart using just the hose. Can you hear it? _____________

WHEN YOU'RE DONE

You probably can not hear the heart beat without the funnel. The funnel is a cone which collects a lot of sound energy and concentrates it in the hose. So when you use the funnel, a lot more energy reaches your ears. That is, the heartbeat is louder.