Coconut Cup Telephone

Discover how sound travels through string using coconut shells, learning about communication devices while connecting to Caribbean island resources.

Caribbean Connection

Using coconut shells instead of paper cups connects this classic experiment to our island resources. The coconut palm is called the "tree of life" in the Caribbean because every part can be used. This activity shows students how local materials can be used for science and communication!

Activity Overview

The Coconut Cup Telephone demonstrates how sound can travel through solid materials. Students create a simple communication device using coconut shell halves connected by string, discovering that vibrations can travel along the string to carry messages. This activity also introduces important discussions about communication and respect for persons with hearing impairments.

Learning Objectives

Understand that sound can travel through solids (string)
Observe how vibrations carry sound from one place to another
Explore how simple communication devices work
Investigate variables that affect sound transmission
Develop awareness of different communication methods
Show respect for persons with hearing impairments (ELO4)

Curriculum Connections (ELO4 - Communication Devices)

Waves, Light & Sound: Sound Transmission

Sound travels through different materials
Vibrations carry sound energy
Simple devices can help us communicate

Social Awareness: Communication and Inclusion

Different ways people communicate
Respecting persons with hearing impairments
Introduction to sign language

Implementation Steps

1Prepare the Coconut Telephones (Teacher Prep)

Clean and dry two coconut shell halves for each pair
Use a small nail and hammer to make a hole in the bottom of each shell
Cut string or fishing line to 3-5 meters for each telephone
Thread string through holes, tying secure knots inside each shell
Prepare several telephones for the class
Note: Paper or plastic cups can be substitutes if needed

2Introduction - How Do We Communicate? (5 minutes)

Ask: "How do we talk to people who are far away?"
Discuss phones, radios, shouting
Show the coconut telephone: "Today we'll make a simple phone!"
Ask: "Do you think we can send messages through this?"
Let students make predictions
Explain we'll test if sound can travel through string

3Testing the Telephones (15 minutes)

Pair up students and give each pair a coconut telephone
Partners walk apart until the string is pulled tight (very important!)
One student speaks softly into the shell while the other listens
Ask the listener: "Could you hear what they said?"
Switch roles so both students experience speaking and listening
Ask: "What happens when you speak? What is the string doing?"

4Experimenting with Variables (10 minutes)

Test: "What happens if the string is loose?" (Sound doesn't travel well)
Test: "What happens if someone touches the string?" (Sound is blocked)
Try whispering vs. normal voice - which works better?
Discuss: The tight string carries vibrations from one cup to the other
When you touch the string, you stop the vibrations
Connect to previous learning about vibrations causing sound

5Extension - Sign Language Introduction (10 minutes)

Ask: "What if someone cannot hear? How do they communicate?"
Introduce sign language as a way to communicate without sound
Teach basic signs: Hello, Thank you, Friend, Please
Practice signing greetings to each other
Discuss: "Why is it important to know different ways to communicate?"
Emphasize respect and inclusion for all people

Sign Language Basics

Teach these simple signs to introduce students to communication for hearing-impaired persons:

Hello

Wave your hand side to side near your face

Thank You

Touch your chin with fingertips, then move hand away

Friend

Hook index fingers together and switch their positions

Please

Rub your palm in a circle on your chest

Activity Variations

Different Strings

Compare fishing line, yarn, and thin wire. Which carries sound best?

String Length Test

Try short (1m) vs. long (5m) strings. Does distance affect the sound?

Three-Way Phone

Connect three cups with string at a central point. Can three people talk?

Secret Message Game

Whisper secret words through the telephone and see if they arrive correctly!

Discussion Questions

"Why does the string need to be tight for the phone to work?"

"What happens when someone touches the string while you're talking?"

"How is this telephone different from a real phone?"

"What if someone cannot hear? How can they communicate?"

Assessment Rubric

Sound Transmission Understanding

Excellent: Explains how vibrations travel through the string
Good: Understands sound travels through the string
Developing: Observes that the phone works when string is tight
Beginning: Needs support to understand the concept

Social Awareness

Excellent: Shows understanding and respect for different communication needs
Good: Participates respectfully in sign language activity
Developing: Shows interest in learning about hearing impairment
Beginning: Needs guidance on respectful discussion

Materials and Resources

Essential Materials

Two small cleaned coconut shell halves per pair
String or fishing line (3-5 meters per telephone)
Small nail and hammer (for teacher to make holes)
Alternative: paper or plastic cups

Preparation Tips

Clean coconut shells thoroughly and let dry completely
Make holes in shells before class (safety first!)
Tie secure knots inside shells so string doesn't pull through
Test telephones to ensure they work well
Find sign language resources or videos to show the class
Consider inviting someone who uses sign language to visit

Materials and Resources

Essential Materials

Two small cleaned coconut shell halves per pair
String or fishing line (3-5 meters per telephone)
Small nail and hammer (for teacher to make holes)
Alternative: paper or plastic cups

Preparation Tips

Clean coconut shells thoroughly and let dry completely
Make holes in shells before class (safety first!)
Tie secure knots inside shells so string doesn't pull through
Test telephones to ensure they work well
Find sign language resources or videos to show the class
Consider inviting someone who uses sign language to visit