To make a home made Stethoscope.
- A tubing piece
- A balloon
- A timer
- Rubber band
- Take a tubing and fit a funnel at both the ends.
- Enlarge the balloon by blowing and then let the air out.
- Cut top third of the balloon.
- Stretch the top of the balloon tightly above the open end of any one of the funnels. You can use a band to hold it in a correct place.
- Sit in a quiet place and keep the end of the funnel with a balloon on your chest, towards the left centre on the skin.
- Keep the other funnel over the ear. You can hear a little beating sound.
- Make use of the timer to count the number of beats you hear in 20 seconds. Multiply this value by three to calculate how much your heart beats in a minute.
- Try doing more tests like running for 5 minutes and check how fast your heart beats.
The doctors listen to your heart beats for two seconds with a stethoscope. The first sound is a low pitched and longer sound while the second beat is higher and shorter sound.