National Aeronautics and Space Administration 

The 

Astro-Not-Yets: 

Sound on 

a String! 

Educator

Guide

For more about Next Gen STEM visit 

www.nasa.gov http://www.nasa.gov/stem/ccp. 
2

The Astro-Not-Yets 

Sound on a String 

Grade Level: K-2 

Suggested Time: 5 days - (30 min each day) 

Day 1 – Inquiry Discussion & Inquiry Activity 1 – Type of String 

Day 2 – Inquiry Activity 2 – String Length 

Day 3 – Inquiry Activity 3 – Type of Cup 

Day 4 – Inquiry Activity 4 – Cup Size 

Day 5 – Final Discussion 

Objectives: Following this activity, students will be able to: 

• Explain how sound travels. 

• Demonstrate the affect different materials 

have on the transmission of sound waves. 

Materials: 

 Multiple types of string: 2m each (examples: cotton 

zzzzzzzzztwine, polyester kite string, nylon monoflament, 

zzzzzzzzzyarn, waxed shoemakers thread, carpet or button 

zzzzzzzzzthread, etc.) 

 Multiple lengths of one type of string (examples: 

zzzzzzzzz2m, 5m, and 10m of cotton twine) 

 Multiple pairs of various types of cups (examples: 

zzzzzzzzzplastic, paper, Styrofoam, tin can, etc.) 

 Pairs of various sizes of one type of cup (2 small, 2 

zzzzzzzzzmedium, and 2 large cups) 

 Buttons, paper clips, metal washers, toothpicks, 

zzzzzzzzzglue, or sealing wax (various methods for attaching 

zzzzzzzzzthe string to the cup) 

 Nail or screw for the teacher to punch holes in the 

zzzzzzzzzcups 

 Optional: Beeswax, shoemakers wax, paraffn wax, 

zzzzzzzzzor surfboard wax to wax the string 

 Photocopies of Inquiry Activity Sheet (or create one 

zzzzzzzzzappropriate for your class) 

 Large plastic baggies and stickers for distributing 

zzzzzzzzzmaterials 

 Chart paper 

 Crayons 

 Computer (optional) 

Next Generation Science Standards (NGSS): 

1-PS4-1. Waves and Their Applications in Technologies for 

Information Transfer: Plan and conduct investigations to provide evidence 

that vibrating materials can make sound and that sound can make materials 

vibrate. Grade: K-2 

1-PS4-4. Waves and Their Applications in Technologies for 

Information Transfer: Use tools and materials to design and build a device 

that uses light or sound to solve the problem of communicating over a 

distance. Grade: K-2 

Common Core Standards for Mathematics 

(CCSS): 

CCSS.MATH.CONTENT.1.MD.C.4. Represent and 

interpret data: Organize, represent, and interpret data with up to three 

categories: ask and answer questions about the total number of data points, 

how many in each category, and how many more or less are in one category 

than in another. 

Teacher Background: How is a rocket launch like a rock concert? If 

you have ever witnessed a rocket launch in person, then you know the roar 

from the engines during launch can be heard and felt miles from the launch 

pad. Sound is a form of energy caused by vibration. Place a ruler on the edge 

of a table or desk so about half of the ruler sticks out over the edge. Use one 

hand to anchor the ruler to the desk and gently push down or pull up and 

release the other end of the ruler. Listen to the sound made by the vibration. 

Now extend the ruler another inch off the table and strum it again. Repeat 

this several times extending the ruler further over the edge each time. What 

do you hear? Notice how the length of the ruler affects the pitch (how high or 

low the note). 

The tuning keys on a guitar adjust the tension on each string and thus 

change the pitch or frequency of vibration. Like a ruler, the guitar string 

vibrates more slowly when it is longer resulting in a lower frequency or lower 

pitch. Pressing the string against a fret (raised metal strip on the neck of the 

guitar) reduces the length of string vibrating, resulting in a higher note. 

When an object such as a guitar string, rocket engine, or speaker vibrates, 

it causes the molecules in the object to move back-and-forth. Neighboring 

particles push into each other and then return to their initial position. Think 

of a Slinky stretched out across a table. With one end fxed, give the other 

end a small push or pull and watch the disturbance travel along the length 

of the Slinky. This exercise demonstrates a compression wave and illustrates 

how sound energy travels. This chain reaction causes surrounding molecules 

to vibrate. Sound is not only transmitted by vibration; it is also detected by 

vibration. Sound waves traveling through air enter the outer ear causing a 

thin membrane called the “eardrum” to vibrate. The vibration travels through 

the middle ear to the liquid-flled inner ear. There it is channeled to the 

cochlea where specialized cells convert the compression waves into electric 

impulses transmitted to the brain via nerve fbers. 

How does tuning a guitar relate to rocket science? Like a guitar, every sound 

and vibration reverberates through the body of a rocket. The difference 

between them is the musician wants to sustain these vibrations and amplify 

the sound while the engineer works to reduce them. By blasting the rocket 

or spacecraft with sound levels past 140 decibels, engineers can verify 

the structural integrity of a rocket and measure its ability to withstand the 

powerful sound-induced shaking of launch and other stages of fight. 

Sound waves travel at different speeds through different mediums: solid, 

liquid, or gas (air). Sound waves travel faster through materials in which 

the molecules are tightly packed (greater density) and quickly return to 

their initial position (higher elasticity). Insulating materials absorb different 

amounts of energy at different frequencies, so these materials are used to 

dampen vibration and contain sound. Sound depends on vibration to transmit 

energy from particle to particle. Consequently, sound cannot travel through 

the vacuum of space. The molecules are so widely spaced the compression 

wave has no medium to travel through. 

In this activity, pairs of students work together to develop a hypothesis for 

how sound travels and then experiment with different types of cups, cup 

sizes, types of string and string lengths to determine the best method to 

transmit sound on a string cup phone. 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp 
http://www.nasa.gov/stem/ccp 

Preparation and Tips 

This activity is spread out over a period of four days with a ffth day to summarize the results. For best results, students should 

work in pairs. Each day the students test one variable and document their fndings on the “Sound on a String” Inquiry Activity 

Sheet. The teacher or student pairs can then combine the individual fndings on large chart paper to create a class graph for 

each variable and discuss any similarities or differences upon completion of the activity each day. On the following day, review 

the whole class results and create a new chart to record the results for the new variable being tested. Save the charts to compare the results from all four days at the end of the week. On the ffth day, you may also incorporate one of the Extensions as a 

culminating activity. Instead of using chart paper, consider using a spreadsheet with graphing capabilities. 

Each pair of students will need materials to construct one string cup phone each day. Prepare the sets of materials ahead of 

time and distribute to students in large plastic baggies. Prepare an extra set of materials to demonstrate how to construct and 

use a string cup phone. 

Precut the string to desired lengths. Thoroughly wash the cups and make sure there are no sharp edges. Use a thumbtack or 

the tip of a nail or screw to pre-punch holes in the bottoms of all cups/cans. Do not make the holes too large or the cups will 

fall off the string. You may also tie the string to a button, paperclip, metal washer, or toothpick inside the cup to keep the string 

from pulling through the hole; or punch two holes, loop the string through both holes, and tie the knot. Glue or sealing wax is 

another method for securing the string to the cup. You may want to recruit parent volunteers or older students to help younger 

students construct their string cup phones and troubleshoot problems. 

Students may color or decorate their string cup phone to personalize them. Include a numbered and color-coded sticker in 

each baggie to place on the phones to differentiate the day/variable of the phones (e.g., 1-red sticker for kite string, 1-blue 

sticker for cotton twine, 1-yellow sticker for nylon fshing line, 2-red sticker for 2m, 2-blue sticker for 5m, etc.). All phones with 

stickers marked 1 indicate these phones were constructed on Day 1 to experiment with string type. The colors of the sticker 

will indicate the specifc type of string (length of string, type of cup, or cup size depending on which day) to make it easier to 

compare results. Students can then use crayons with the same colors to record their fndings. Remember to change only one 

variable each day and be consistent with all other materials for each phone. For example, it is important when you are testing 

various types of cups that all of the phones use the same type and length of string. 

It may be helpful to model the proper use of a string cup phone before students test their phones. Demonstrate how the string 

must be pulled tightly for the vibration to travel through it. Your hand will dampen the vibration and diminish the sound, so 

attempt to hold the cup with as little of your hand touching the surface as possible. Remind students how they should whisper 

into the phone to allow everybody to hear their own partner. Have students practice soft talking with their partner before the 

activity begins. 

After student pairs complete the construction of their string cup phone, set up tables around the room for conducting the experiment. Assign three or four pairs of students to each table depending on how many types of phones will be tested. Include a 

station for each type of phone (red station, blue station, yellow station, etc.). Each pair of students will then rotate through the 

stations at their table recording their observations to determine which variable is being tested that day (type of string, string 

length, type of cup, or cup size), create a hypothesis about how the variable will affect the sound transmitted (loudness or 

clarity), experiment by talking into each string cup phone, and then record their fndings. 

For a condensed approach to this check out the activity Sound on a String: Center Activity lesson. 

NGS: The As tro-Ne t-Ye ts: Sound on a String! 3
You can demonstrate the procedure below for students prior to engaging in the inquiry activities. Depending on the student level, you may want to display this sequence in a sequential picture diagram on 

the board or print the written instructions for your students. 

1. Thread string up through the hole in the bottom of cup. 

2. Tie a knot on the end of the string inside the cup. You may need to tie several knots on the 

end to make the knot large enough and prevent the string from slipping out of the hole. (See 

paragraph 3 in the Preparation and Tips section above for other suggestions for attaching the 

string). 

3. Repeat steps 1 and 2 with the second cup. 

4. Stand far enough apart so the string is pulled tightly and whisper into the cup while your partner places his or her ear near the opening of the other cup. 

5. Rotate through each station and record your results on the Inquiry Activity Sheet. 

6. Post your results from the Inquiry Activity Sheet onto the class graph. 

Inquiry Discussion: 

Inquiry Activity 1 (Day 1): 

• Types of string (must use the same length of string and use identical cups) 

{ 2m of polyester kite string 

{ 2m of cotton twine 

{ 2m of nylon monoflament (fshing line) 

{ Use whatever you have available including different material/fbers (natural and synthetic) as 

well as different thickness/weight. 

• Discussion questions to follow the activity: Did the type of string affect the loudness or clarity of your 

partner’s voice? Which string would you select? Why? 

Inquiry Activity 2 (Day 2): 

• String length (must use the same type of string and use identical cups) 

{ 2m 

{ 5m 

{ 10m 

{ Experiment with whatever lengths are convenient for your space. If you have a long straight hallway, then you may try an even longer string. 

• Discussion questions to follow the activity: Did the length of the string affect the loudness or clarity 

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Procedure for Inquiry 

Activity 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp 4
5

Inquiry Activity 3 (Day 3): 

• Types of cups (must use the same length and type of string) 

{ Plastic 

{ Paper 

{ Styrofoam 

{ Tin can (or any type of metal) 

{ Try to fnd cups as close to the same shape and size as possible. 

• Discussion questions to follow the activity: Did the type of cup affect the loudness or clarity of your 

partner’s voice? Which cup would you select? Why? 

Inquiry Activity 4 (Day 4): 

• Cup sizes (must use the same length and type of string and use the same type of cup) 

{ 8 oz 

{ 10 oz 

{ 16 oz 

{ Use whatever sizes are available as long as you have a small, medium, and large for one of the 

following: plastic, paper, Styrofoam, or metal 

• Discussion questions to follow the activity: Did the size of the cup affect the loudness or clarity of 

your partner’s voice? Which size would you select? Why? 

Final Discussion: 

Use the Background Information and class chart to guide the following discussion questions and stimulate interest in further investigation. 

• What is sound? 

• How does sound get from one place to another? 

• Why is vibration important? 

• How do we make sound? 

• How do we hear sound? 

The Astro-Not-Yets: Sound on a String! (continued) 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp 
6

Have students explain how they determined which variable was being tested each day or 

at each center. Discuss how the materials affected the sound and conduct a class debate 

about creating the “best” string cup phone with the given materials. Collect and review 

completed “Sound on a String” Inquiry Activity Sheets. 

Extensions: 

• Allow students to demonstrate and/or present their fndings with the class as part of the 

fnal discussion. 

• Give each student the opportunity to create the optimal string cup phone by selecting a 

string length, type of string, cup size, and type of cup. Assemble the phone and allow students to take it home to teach their family about sound waves. 

• Have students brainstorm ideas to improve the design of the string cup phone using the 

same or different materials. Then have students test their designs. 

• Test other variables such as the method for attaching the string to the cup or waxed string 

versus unwaxed string. 

• Use the web resources below, or demos described in the Background Information to research more about sound and fnd additional sound activities such as the Shoebox Guitar, 

Musical Tube, or Super Sound Cone. 

• Team up with a music teacher to let students investigate how different instruments produce 

sounds. 

Web Resources: 

www.grc.nasa.gov/WWW/K-12/TRC/Aeronautics/Musical_Tube.html 

(Musical tube activity) 

www.philharmonia.co.uk/thesoundexchange/sound_samples/sample_libraries/ 

(Collection of samples from single notes to full orchestra) 

https://spaceplace.nasa.gov/sound-cone/en/ 

(Directions for constructing a Super Sound Cone) 

Web sites may provide teachers and students with background information and extensions. Inclusion of a resource does not 

constitute an endorsement, either expressed or implied, by the National Aeronautics and Space Administration. 

Assessment 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp 
The Astro-Not-Yets: 

Sound on a String! 

Student Name: _________________________________ Date:__________ 

Directions: Fill in the blank and draw what you saw during your experiment. 

Day 1: 

Before: 

1. I think the string made of ____________ will make the loudest sound. 

After: 

1. The string made of ____________ made the loudest sound. 

2. The string made of ____________ sounded the clearest. 

This is what our experiment today looked like: 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp 
The Astro-Not-Yets: 

Sound on a String! 

Student Name: _________________________________ Date:__________ 

Directions: Fill in the blank and draw what you saw during your experiment. 

Day 2: 

Before: 

1. I think the string that is ____________ long will make the loudest sound. 

After: 

1. The string that was ____________ long made the loudest sound. 

2. The string that was ____________ long sounded the clearest. 

This is what our experiment today looked like: 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp 
The Astro-Not-Yets: 

Sound on a String! 

Student Name: _________________________________ Date:__________ 

Directions: Fill in the blank and draw what you saw during your experiment. 

Day 3: 

Before: 

1. I think the cup made of ____________ will make the loudest sound. 

After: 

1. The cup made of ____________ made the loudest sound. 

2. The cup made of ____________ sounded the clearest. 

This is what our experiment today looked like: 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp 
The Astro-Not-Yets: 

Sound on a String! 

Student Name: _________________________________ Date:__________ 

Directions: Fill in the blank and draw what you saw during your experiment. 

Day 4: 

Before: 

1. I think the ____________ size cup will make the loudest sound. 

After: 

1. The ____________ size cup made the loudest sound. 

2. The ____________ size cup sounded the clearest. 

This is what our experiment today looked like: 

NGS: The As tro-Ne t-Ye ts: Sound on a String! http://www.nasa.gov/stem/ccp