Make a stethoscope
Build a simple homemade stethoscope using tubing and funnels to listen to heartbeats and breathing, learning about sound, vibrations, and safety.
About this activity
Build a simple homemade stethoscope using tubing and funnels to listen to heartbeats and breathing, learning about sound, vibrations, and safety.
What you need
Step by step
- 1
Step 1
Lay out all your materials on a clean table so you can see everything.
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Step 2
Wash the funnel and the tubing with soap and water and dry them with a towel.
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Step 3
Measure the tubing to about 30 cm using the ruler and mark where to cut.
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Step 4
Cut the tubing at your mark with scissors so you have one neat piece.
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Step 5
Push one end of the tubing onto the funnel stem until it fits snugly.
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Step 6
Wrap strong tape around the funnel stem and tubing joint to make an airtight seal.
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Step 7
Make a soft ear pad by flattening a small piece of cotton and place it gently over the open end of the tubing without pushing it inside the ear.
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Step 8
Tap the funnel lightly once to check that sound travels through the tubing before using it on a person.
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Step 9
Ask an adult to help place the funnel flat against the left side of the chest just below the collarbone where the heartbeat is strongest.
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Step 10
Hold the open end of the tube a few centimetres from your ear without inserting it and stay very still to listen for heartbeat and breathing sounds.
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Step 11
If you can’t hear clearly move the funnel a little and try different gentle pressures until the sounds are louder.
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Step 12
Share a photo and what you discovered with your homemade stethoscope on DIY.org
Fun facts
How do you build a simple homemade stethoscope to listen to heartbeats and breathing?
To make a simple stethoscope, cut a 30–50 cm length of flexible plastic tubing. Attach a small funnel or cup to one end with strong tape to act as the chest piece; seal gaps with extra tape. Fit another funnel (narrow end inward) to the opposite end or slightly flare for ear cups. Place the chest funnel against the chest or back and listen through the tubing. Adults should help cutting and hold the funnel while the child listens.
What materials do I need to build a homemade stethoscope?
Materials: flexible plastic tubing (about 30–50 cm), two small funnels or plastic cups, strong tape or waterproof duct tape, scissors or craft knife (adult use), marker to mark cuts, optional soft foam or cotton to pad ear ends, rubbing alcohol and cloth for cleaning. Use tubing with an inner diameter around 8–12 mm for best sound. Substitute empty paper cups and straw for a very simple version. Supervise all cutting and taping.
What ages is making a homemade stethoscope suitable for?
Suitable for ages 5 and up with adult supervision; children 8–12 can build most steps with minimal help. Younger preschoolers (3–4) can participate by holding funnels or listening while adults do cutting and taping. The activity teaches observation and fine motor skills, so adapt complexity: provide pre-cut tubing and stronger tape for younger kids, and involve measurements and hypotheses for older children to explore sound science.
What safety tips should I know when making and using a homemade stethoscope?
Safety tips: always supervise cutting and taping, and never insert funnels or tubing into a child’s ear canal. Use soft padding on ear ends and avoid very tight seals to prevent discomfort. Clean parts with rubbing alcohol before and after use. Explain this is a learning toy, not medical equipment—do not use it to diagnose illnesses. Watch for small parts that could be choking hazards, and discontinue if the child feels pain, dizziness, or ear discomfort.
Watch & Learn
Need help?
What can we use if we don't have the funnel or the clear tubing listed in the materials?
If you don't have a funnel or clear tubing, cut the top off a clean plastic water bottle to make a funnel and use a long, clean flexible drinking straw or clear vinyl tubing about 30 cm long as the tube, then attach and tape them just like in the steps.
I tapped the funnel but still can't hear a heartbeat—what should I check?
If tapping the funnel doesn't help, make sure the funnel stem and tubing joint are taped tightly for an airtight seal, that the cotton pad isn't blocking the open end, and reposition the funnel on the left chest or try different gentle pressures as described.
How can I adapt this activity for a 3‑year‑old versus a 10‑year‑old?
For a 3‑year‑old, have an adult do the measuring, cutting, and chest placement while the child listens a few centimetres from the tube and helps tap the funnel, whereas a 10‑year‑old can measure 30 cm, cut the tubing with supervision, add the cotton ear pad, and experiment with moving the funnel to find the strongest heartbeat.
How can we make the stethoscope more fun or advanced after finishing it?
To extend the activity, decorate the funnel and tubing with safe stickers, make a two‑tube binaural version by adding a Y‑connector or taping a second piece of tubing to the funnel stem so two people can listen, and then compare and photograph your findings to share on DIY.org.