Instructions

  • 1

    Here are some of the materials you can use

    • instrument (homemade or real)
    • 2 paper cups (6-oz. [170-ml] or larger)
    • paper towel tubes (or visit a hardware or home supply store and find a 3-ft [0.9-m] section of a plastic, flexible hose)
    • scissors 
    • string (thin, such as kite string)
    • tape (duct or clear)
  • 2

    Prepare ahead of time

    • Have paper and a pencil ready to write down ideas and sketches as you design.
    • Think about music you listen to. Do you turn it up loud to hear it, or do you listen to it down low?
    • You will need an instrument to use with your headphone. You can use a real instrument or a toy instrument or you can build a rubber band instrument out of a box wrapped with different sized rubber bands.
  • 3

    Think about the challenge

    • Why do people use headphones?
    • How do headphones work? 
    • How does the music go from the instrument to your ears?
    • How are music and other sounds made? 
    • TIP: Headphones pick up an instrument’s vibrations and carry them to your ear.
    • TIP: The rapid vibrations, or back and forth movements, are what causes sound waves that travel through the air. Vibrations are what make sound.
    • TIP: Inventors are always looking for ways to improve things or meet people’s needs—including making it easier for people to hear music! Music is important to people and learning how to make different ways for people to listen to music is fun and exciting.
  • 4

    Think about and write down your ideas

    • What kinds of things will carry sound waves to your ears? (Cardboard tube, plastic tube, string telephone, radio system and transmitter)
    • Where will you place the headphone on your instrument?
    • Will you add an earpiece, such as a cup, to the end of the tube or string?
  • 5

    Look at the materials

    • Which material might carry the most sound to your ears? 
    • How does a string telephone bring the sound waves to your eardrums?
    • How will you attach the headphone to your instrument?
    • TIP: A tube will trap the air inside. The sound waves vibrate the air. Then the air vibrates in your eardrums, reproducing the sound. 
    • TIP: A string telephone uses solid materials to carry sound to your ears.
    • TIP: When a person speaks into a string telephone cup, the voice produces sound waves that travel into the cup and get the string vibrating. The string carries these vibrations to the second cup. This cup begins vibrating and moves the air in and around it, reproducing the original sound, which can be heard by the person holding the second cup.
  • 6

    Design and build the headphone

    • Decide what material you will use to build your headphone. 
    • Prepare your tubes or thread and build the headphone.
    • TIP: Keep the string or tube length as short as possible because sound diminishes, or lessens, with distance.
  • 7

    Design and build the headphone (continued)

    • Play your instrument and find where the vibrations are strongest.
    • Decide where you will attach the headphone to your instrument.
    • TIP: If you want to transmit as much of the vibration as possible, find where your instrument is vibrating the most. Place your hand on different parts of your instrument and play the instrument (or have someone else play it) to find where you feel strong vibrations.
  • 8

    Attach the headphone to the instrument 

    • Will you place the string or tubes on the inside or outside of the instrument? 
    • Make your choice and attach the headphone.
    • TIP: If the string is not carrying the sound waves, try using a double string to capture twice the number of vibrations from your instrument. Or make sure the string is firmly attached to the instrument.
  • 9

    Try out your headphone system

    • Start playing your instrument.
    • Put your headphone on and listen.
    • TIP: If you want to increase the vibrations, try moving the placement of the headphone. Or remove any extra tape, bridge material, or anything that might reduce the vibrations.
    • TIP: If your strings are not staying tight, try adding weights or have a partner hold down the instrument to keep it in place.
  • 10

    Did you know?

    • Don’t Turn Up the Volume!
      Sound levels in the waters off the coast of California are cheating animals out of their natural environment in the Pacific Ocean. All the noise in the water is causing whales to get flustered, lose their way, and even become beached on the shore.

      Over the past fifty years, the noise in the Pacific Ocean has become 10 times louder because of the rumbling of shipping vessels, research equipment, and sonar systems. All these machines use the same range of sound frequencies that whales use to communicate with one another. Because these whales can no longer hear or communicate with other whales, they are losing their way. Back in the 1940s, blue whales were able to hear up to 1,000 miles (1,600 km)—but today they are only able to hear 100 miles (160 km) away! Looks like someone needs to invent sound-blocking headphones for the whales!
  • 11

    Try this next!

    • Make your headphone hands-free. Modify your headphone so it can be used without holding it with your hands. Design a headpiece so you can play your instrument with both hands.
    • Decorate your sound system. Decorate and revise your instrument and headphone to be something your friends will want to wear.