Whistling waveforms
Practical Activity
for 11-14
In this activity, students download an oscilloscope app onto a laptop or phone to investigate pitch and loudness. You can use it to introduce waveforms of sounds.
Equipment
Each student will need:
- A laptop (or a smartphone)
- Two different sized bottles with long necks (optional)
- A copy of the student instruction sheet
Teaching notes
Students should start by watching the video as described on the instruction sheet before downloading an oscilloscope onto a laptop or phone. For a Windows laptop, Soundcard Oscilloscope is ideal as it provides a large display for easy comparisons of wave traces. If your students do not have access to a laptop, alternative free apps for smartphones or tablets are suggested on the activity sheet. If you recommend a different one, make sure it has a pause function.
If students can’t whistle, they can ask another person at home to be their sound source. Alternatively, they could blow over bottles or use a musical instrument such as a guitar or a recorder. They should see that when the sound is louder the peaks of the waveform are bigger, and that when the pitch is higher the peaks are closer together.
Learning outcome
Students draw waveforms for sounds with different volumes and frequencies.
With thanks to Christian Zeitnitz for permission to use Soundcard Oscilloscope