Sound Cups

1. Use one color of plastic cups (red, for example) to assemble the Sound Cups. Set aside the other color of cups (blue, for example), for participants to use in their investigations.
2. Before participants arrive, place one or more of the same type and number of small objects into two of the red cups to make a matched pair. For example:
   • Place 5 rubber bands in one cup, and 5 rubber bands in a second cup
   • Place 6 dried beans in one cup, and 6 dried beans in a second cup
   • Place 3 cotton balls in one cup, and 3 cotton balls in a second cup

   Each participant will need one Sound Cup, and every Sound Cup will need a match within the group.

3. To test how each cup will sound, place an empty cup over the object-filled cup, hold the cups together, and give them a shake. You’ll want each Sound Cup to have a distinctive quality that the participant will be able to hear.

   Note: If you find yourself running out of unique sound-making objects, you can add variety by making one matched pair from a single paper clip, for example, and another from 5 paper clips, and so on.

4. Continue in this way, making unique-sounding pairs, until you have enough for everyone in the group to have one Sound Cup. Be sure every cup has a match so everyone will be able to participate! Keep the pairs of cups together as you work. They’ll need to be filled, sealed, and coded (see Steps 5 and 6) before use.
5. When you’ve made enough pairs, seal each filled cup by placing an empty plastic cup on top and taping the two together with masking tape. (Be sure the objects inside are well hidden and secure: People will be shaking them!)
6. As you finalize your Sound Cups, use a marker to code the bottoms of each pair so you’ll be able to spot its correct match. One easy way to do this is to write a number on the bottom of each such that the sum of the digits is the same. For example, 44 and 602 would be a matched pair. As long as you don’t reveal the code, you’ll be the only one who knows how the Sound Cups go together. If you want, you can write out a (secret) master sheet to keep track of the cup numbers and their contents.
7. When all the red Sound Cups have been assembled, sealed, and coded, mix them up and set them out for participants to choose.

To begin, have participants each choose a red Sound Cup. Ask people to gently shake the cup they’ve chosen and try to find the person who has a cup that sounds the same. If you want, you can instruct the group to do this exploration without speaking—the sounds of the cups should guide participants to find a match within the group. If participants have trouble finding a match, ask all unpaired people to raise their hands so that they can narrow their possibilities. It is ok if someone ends up with a partner that is not a perfect match.

Once participants have made their best attempts to find their correct partners, have pairs work together to try to build an identical Sound Cup using the materials provided on the trays. No fair looking inside their red cups! They need to build their own blue ones (or whatever two colors of cups you’ve used) by sound only.

Finally, bring the whole group together to share their processes and their findings. Have each pair present their work, demonstrating the sounds of the original cups one at a time, and then the sound of their reconstructed cup. What process did the presenters use to make their own Sound Cup? How well did they match the sound? What do people notice?

At the end of their explorations, many people will want to know if they were “right.” Do not open them up, and instead use the opportunity to emphasize an important principle: In science, it often isn’t possible to appeal to a higher authority or look inside the object we are observing. Instead, we must rely on our own observations and investigations to answer our questions. This is an essential part of the scientific process.

Sound Cups present an excellent opportunity to think like a scientist. Given the problem of finding the Sound Cup that matches yours, you start using your senses—your sense of hearing and your sense of touch—to make observations. As soon as you shake or rattle your Sound Cup, you are carrying out an investigation, gathering data, and analyzing your results. Plastic cups make wonderfully resonant chambers, allowing simple objects to sound very mysterious. Only through careful observation will partners be able to find each other and then make a matching Sound Cup.

This activity works well in a science classroom and can be used to randomly group students into pairs. At the Exploratorium, we like to use this activity at the start of the school year, asking students to introduce his/her Sound Cup partner as part of a “getting to know you” activity. If there are any issues, you should be able to look at the codes to help partners find one another.

If you want to evaluate aspects of this activity, here are a few points to consider:

• Did each student find someone whose cup sounded like theirs?
• How well did the students match their own Sound Cups to the Sound Cups they were given?
• What science skills and practices did students use as they worked with one another? To create their Sound Cups?

If you want to add a writing component to these investigations, you can have each student write about the sound that their cup made:

• Can they describe what it sounded like?
• Did it remind them of anything?

You might also ask them to write about their experiences:

• What was it like working with a partner to create a matching Sound Cup?
• What did they try? What science practices did they use?
• What finally worked?

This Snack was adapted from an original activity created by Mike Petrich and Karen Wilkinson of the Exploratorium’s Tinkering Studio.