Sound Investigation with the micro:bit

1. Introduce the Activity
   • Discuss: 
     1. If someone is playing music across the room, does it sound the same as when you’re standing right next to it?
     2. Why does sound change with distance?
     3. Does sound disappear or just get weaker? 
2.  Introduce the Investigation 
   • We’re going to test how distance affects sound. Explain the setup:
     1. One sound source stays in the same place
     2. The micro:bit measures sound at different distances
   • This is called a fair test—we only change one variable: distance.
3. Code the micro:bit 
   • Walk students through creating the following code or use the provided link to share the completed code with students. 
   • 
4. Prepare the Experiment
   • Guide students:
     1. Place sound source at fixed location
     2. Mark measurement points (every 2 meters)
     3. Assign roles (reader, recorder, measurer, device handler) 
   • Tip: Keeping everything else the same helps us trust our results.
5. Collect Data
   • Now we gather evidence. Students measure sound at regular intervals from the source
   • Steps:
     1. Place micro:bit next to sound source
     2. Press Button A to take a reading
     3. Press Button B to display the value
     4. Record the data
     5. Move 2 meters away
     6. Repeat at multiple distances
   • Tip: Encourage multiple readings at each distance for accuracy
6. Analyze Results
   • Discuss:
     1. What pattern do you notice?
     2. Does sound increase or decrease with distance?
     3. Were your results consistent?
   • Sound gets fainter as distance increases
7. Discuss & Connect
   • This is how scientists study sound in the real world. Connect to real-world uses:
     1. Concert and speaker placement
     2. Noise pollution studies
     3. Wildlife monitoring
     4. Building design 
8. Reflection 
   • Discuss:
     1. What did your data show?
     2. How did the micro:bit help you investigate?
     3. Why is it important to keep tests consistent?
     4. What would you test next?

• This lesson requires a continuous sound source at a fixed volume; you might like to play micro:bit’s tone.mp3 file from your computer (do not use a sound source which could vary in volume, such as a drum)
•  Recommend splitting kids up in small groups where sounds can’t overlap (ie. closet, hallway,etc.) OR teacher plays ONE sounds source
•  Tips (provided in lesson plan)
  • Conduct the experiment in a large space with no obstacles, so that you can easily measure distances from the sound source in a straight line.
  • Conduct the experiment in a quiet space.
  • For more accurate results, take a few readings at each distance interval and work out their average.

Students can:

• Graph their data (distance vs sound level)
• Compare different environments (quiet vs noisy)
• Test different sound sources
• Investigate obstacles (walls, materials)