Helping Students to Understand Sound and Light Waves

Teaching about sound and light waves to middle school students can be tricky. They can't see them and the concept is difficult to grasp. Here are some teaching tips to help students understand the concepts behind sound and light waves.

Teaching About Sound and Light Waves

Opening the Unit

• Ask students about their experiences with waves. Allow students to discuss all kinds of waves, including water waves, radio waves, microwaves and even doing "the wave" at a sports stadium.
• Have students put their hand on their throat while talking or humming and feel the vibration.
  
  
  
  
  
• Whether or not they bring it up, discussing doing "the wave" is actually a great way to explain what waves are: energy. Help students to notice that when doing the wave, the people move up and down but the energy of the wave moves to the side.

Observing waves

• Ask students if they've ever felt discomfort from hearing a loud noise. Discuss the impact of the energy on the eardrum.
• Sprinkle some salt or sugar crystals on a piece of plastic wrap that has been pulled taut across a bowl. Play or make a loud sound nearby. Watch how the energy of the sound waves makes the crystal move!

Teach vocabulary associated with sound and light waves

• Students need to know vocabulary associated with sound and light waves, including:
• frequency
• wavelength
• amplitude
• pitch
• Doppler effect
• reflection
• refraction
• spectrum
• speed of light
• speed of sound
• One way to teach these words is with diagrams. Another way is to use a slinky. Slinkys are terrific for modeling longitudinal waves to help students understand how they're different from transverse waves. Have two students stretch a slinky and then make waves. You can show students, for example, how to measure a wavelength in a longitudinal wave. 
• Use multimedia to help students understand the concepts. There are lots of videos and simulations out there. Bill Nye the Science Guy is one example. Here's a video about using a tuning fork to visualize the energy of sound waves and water waves.
• Having students play with toy xylophones and make rubber band guitars is a great way to help reinforce their understanding of pitch and how it is affected by the size of the bars or strings on the musical instrument. Use a slide whistle to show how lengthening the whistle deepens the pitch. You can also show a video of a trombone being played.
• Use this super interesting sound waves reading passage to help reinforce the concepts behind waves—particularly sound waves.

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Fun and easy hands-on labs to teach about sound and light waves

Have students use a spoon and a piece of string to test the effect of different mediums on how sound waves travel.

Use a flashlight and a mirror to show students that the the pupil in their eye changes size depending on the amount of ambient light. Use this as a springboard to discuss how light waves bounce off items and travel to our eyes and this is how we see.

Make use of the concept of afterimages to help students better understand how the eye sees color.

Find all of these fun and easy labs in this bundle of sound and light waves experiments.

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Have you visited my FREEBIE page? Check that out for a free resource for this unit.