Sound waves and waves in general are concepts that I’ve found many students have difficulty understanding. These are concepts that deal with understanding how energy is transmitted from one place to another through a scientific model. Why are these concepts difficult? Firstly it is abstract. You can’t see waves. When you speak or hear music you can’t see the waves coming out from the source and travelling to your ear. You can’t see the vibrations of particles. Secondly learning about the transmission of waves comes with a lot of academic language. Here’s just a sample of academic scientific jargon you’ll hear when you sit in a lesson learning about waves:
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Equilibrium
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Particles
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Transmission
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Transfer
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Amplitude
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Frequency
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Period
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Wavelength
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Compression
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Rarefaction
Due to this, learning about waves is particularly challenging for students who are also English language learners. Not only do they have to deal with difficult and abstract scientific concepts, they also have to deal with the intense bombardment of academic language.
This year I have a Year 9 class who are students learning English as a second language. I didn’t want to start the topic with a waveform diagram and pointing out what is an amplitude, etc. I planned a learning sequence that will move them from concrete to abstract, and from everyday language to academic language.
The first concept I wanted them to understand is that sound is vibration, or things shaking back-and-forth very quickly. We used the good ol’ tin can phones for this. We also did an experiment where students used a vibrating tuning forks to tickle their noses and make tiny splashes with a beaker of water (I thought they would find these experiments too boring, but they absolutely loved it). Every single student left that lesson knowing that sound is caused by vibrations.
The second concept I wanted them to understand is that we can represent sounds as waves. Students used Audacity to record their voices and experiment with how the loudness and pitch of their voice affected how the sound wave looked like on Audacity. We also experimented on whether saying “Hello, My name is ____” in English and students’ first languages had a difference in pitch.
Here’s a video on Audacity. It’s a free program that can be downloaded.
Students worked out from this Audacity activity that the higher pitched their voices were the more squashy the waves were. They also worked out the louder their voices were the taller the waves. I was happy for them to use the words “squashy” and “high” to describe the waves for the time being.
The following lesson I introduced frequency and amplitude. By now the students had a conceptual understanding of the relationship between sound and vibrations, the relationship between pitch and “squashiness” and the relationship between volume and the tallness of waves. They now just had to replace “squashy” with frequency and tallness with amplitude.
I really like the strategy of teaching a concept with everyday language first and then introducing the scientific terms after students have actually understood it. Science is hard enough without a bunch of difficult words bombarding students as well.