Difficulty Beginner
Time Required Short(2-5 days)
Prerequsites none
Material Avaliability Readly avalible
Cost Low($20 - $50)

Adult assistance is needed for cutting tubing and hoses with the scissors.


Doctors use many complicated tools to check the health of patients. But you can make some medical tools at home—like a stethoscope! A doctor uses a stethoscope to listen to a patient's heart. In this science project, you will make three of your own homemade stethoscopes and figure out which stethoscope design works best and why.


Build three different homemade stethoscopes and determine which works best and why.

Materials and EquipmentEdit

  • Large plastic funnels (3)
  • Small plastic funnels (2)
  • Plastic tubing, at least 15 inches long
  • Ruler or measuring tape
  • A pen that can write on plastic
  • A pair of strong scissors or utility knife
  • Small garden hose, at least 15 inches long
  • Electrical tape
  • Duct tape
  • A cardboard tube from a paper-towel roll
  • A helper
  • Lab notebook
  • Optional: Graph paper


Ever wonder how the doctor can hear your heart beating? You have probably seen that the doctor uses a tool called a stethoscope to do this. A stethoscope is a long, thin plastic tube that has a small, flat disc or hollow cup on one end and earpieces on the other end. The doctor puts the flat disc or hollow cup on the patient's body, and the earpieces go into the doctor's ears. Look at Figure 1 below to see a photograph of a stethoscope.

Figure 1. A doctor uses a stethoscope, like the one shown above, to hear small sounds inside a patient's body, such as the sound of the heart beating.

Using a stethoscope, the doctor can hear sounds inside a patient's body. How does it work? The disc and the tube of the stethoscope amplify small sounds, or make sounds louder. This amplified sound travels up the stethoscope's tube to the ears of the doctor, who hears the sound through the earpieces.

A doctor can use a stethoscope to listen to a patient's heart, lungs, and other small sounds within the body. Heartbeats can easily be heard using a good stethoscope. Every time a person's heart beats, the heart contracts and pushes blood through the body. This blood is full of oxygen that the heart helps deliver to the rest of the body, while picking up nutrients and taking them to other parts of the body. Very good stethoscopes can let the doctor hear these amplified heartbeats as well as even quieter sounds in a patient's body.

What parts of a stethoscope are most important for making it work well? Why would some stethoscopes amplify sound better than others? In this human biology science project, you will make three different homemade stethoscopes and investigate why one stethoscope design works better than other designs.

Terms and ConceptsEdit

  • Heart
  • Stethoscope
  • Amplify
  • Heartbeats


  • How does a stethoscope work?
  • What do doctors use stethoscopes for?
  • Why do you think one stethoscope would work better than another?


Community content is available under CC-BY-SA unless otherwise noted.