After you’ve completed this experiment, you can try making your own sound-to-light transformer as shown below. Using the properties of sound waves, we’ll be able to actually see sound waves when we aim a flashlight at a drum head and pick up the waves on a nearby wall.


Here’s what you need:


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22 Responses to “Seeing Sound Waves using Light”

  1. Cynthia Farrer says:

    We put Beethoven up to the drum. Boy, did it work well!–(Sam Farrer age 9)

  2. Madlen Penn says:

    I do this experiment in a much more simplified way… Granted, no cool lasers are involved in my version, but it gets the job done! 🙂

    I make my drum (can + balloon), set it on the table, and place 4-5 rice kernels on it. The rice picks up the vibrations readily! We have made the kernels dance like crazy using everything, from our best singing voices, to the most ridiculous noise-makers.

  3. Hi Brook,

    I am not quite sure what you’re asking… try again?

  4. Brook Batzel says:

    can satic electric light do it i can see it when i rud my head on my pillow and im not allowed to do YouTube.

  5. You need it to fasten well to the can, well enough for the vibrations to transfer from the can to the drumhead. It also needs to be stretchy and elastic, so it can move when disturbed and also return to its original shape when at rest.

    Try different things and see how it goes!

  6. Malcolm Smith says:

    Hi Aurora,

    Do you know any alternatives to a balloon? Do you just need something to go taunt around the can? Could I use something like baking paper?

    Thanks! Juliette, (14)

  7. You know, I was just looking at that particular experiment and thinking of a better way to do it, and here you are writing about how it was hard to do! I’ll plan on doing another video – it’s basically a microphone that you can see the sounds waves on. Thanks for your feedback!

  8. Lisa Main says:

    This was was very difficult for us. We tried flashlights and highly reflective metal lids and coins. We bought a laser pointer and small mirror identical to yours. We tightened the balloon, we moved the chair holding the laser all the way across the room. They that *maybe* they see a slight wiggle when I clap my loudest. The only thing I can think of is that we have the slightly larger size of can. But, if anything, I would have thought that would have made it better?

  9. Oh sorry about that! I think I used a regular old flashlight from the back drawer… try it and see what you find! I think a laser works as well.

  10. Krista Moretz says:

    What’s the best “strong” flashlight to use… you didn’t demo at the end of your video.

  11. Danielle Zigmont says:

    does it have to be hot glue?

  12. Sure – anything that is still enough to hold its shape when you remove the ends (which is where most of the structural strength comes from, as you’ll find out!). Let me know what you find!

  13. Does it have to be a can? None of the ones we have can have both ends removed by a can opener. Can I use a cup with the bottom removed?

  14. Sure – see comments below. Mirrors work best of course, but get as inventive and creative as you can!

  15. Vanessa Antonsen says:

    can we use a reflective object instead of a small mirror?

  16. How about a piece of mylar, like from a balloon? Or a shiny piece of metal, like a coin? Or a mirror from a cosmetics case?

  17. Emily Crawford says:

    Aluminum foil does not work. It doesn’t really reflect the light right. I’ll try something else.

    -Mary Crawford (age 13)

  18. It needs to reflect the beam, so anything that does that should work. Let me know what you find out!

  19. Emily Crawford says:

    Does it have to be a mirror, or can you just use something small and reflective?

    -Mary Crawford (age 12)

  20. sevy keble says:

    This is awesome! The reflection moved!

  21. Look like our server had a hiccup. Go ahead and try again.

  22. Anita Mullins says:

    Hi,

    This video does not start under IE 8, Chrome, or Firefox. The YouTube videos are starting just fine.