This activity shows how the vibrations made by tapping the drumhead move down the cardboard tube and push the air out through the little hole at the opposite end, much like they travel down our ears. The pitch or tone of sound waves is measured in Hertz. The class sits down in a circle. One person volunteers to wear a blindfold and sit in the middle. The blindfolded student must point in the direction of the noise.
Many different players can take a turn at being blindfolded.
They must form a zigzag pattern with an angle of about 90 o between each tube. Without changing that angle, place a square of posterboard facing the adjoining end of the first and second tubes, another square of posterboard facing the ends of the second and third tubes, and a third piece of posterboard facing the ends of the third and fourth tubes. Place a microphone hooked to a tape recorder at one end of this contraption. Set a ticking metronome or alarm clock at the opposite end, but away from the opening of the first tube. The tape recorder will record either nothing or a very faint sound.