During February it seems the whole world is covered with hearts as a symbol of love. Your heart might beat faster when you think of that special someone. But it also keeps the rest of you body supplied with oxygen and nutrients that your muscles need. You heart makes it possible those muscles to reach out and hold their hand or give them a warm hug.
You can even listen to your heart, or the heart of the one you love, any day of the year using a homemade stethoscope.
The earliest stethoscopes were simply wooden tubes. You can use a paper towel tube or small length of pvc pipe and hold it to a friends chest with your ear on the other end. If you are very quiet and still you should hear the “thump-thump” of their heart. These types of stethoscopes are still used to listen to the heartbeat of a baby before it is born!
You can improve your stethoscope by attaching funnels to each end so that it gathers more sound. Stretch a balloon tightly over the funnel you place over the heart. The tight rubber balloon will vibrate and amplify the sound. Next replace that stiff tube with something longer, shorter, thinner or more flexible to see if that makes the sound clearer and louder. You can even attach earpieces from a pair of old earphones and add two tubes instead of one so that you can use both ears to listen. Now your stethoscope might resemble the one the doctor used at your last check up. How else can you improve your stethoscope design?
Explore more!
Build the stethoscope and listen to your friend’s heartbeat. Can you count the number of beats in 10 seconds? Have them do jumping jacks for 30 seconds and then count their heartbeats again. Try listening to other body parts such as your stomach when you’re hungry or a cat when it purrs.
Resources
- Stethoscope , from KidsHealth
- What is a stethoscope and how does a stethoscope work? , from Acoustic Heart
- The evolution of an essential tool , from 3M Littmann Stethoscopes
- Stethoscope Science, from Scientific American
