The Science of Sound
Buzz, crackle, bang — sound is everywhere! Use these fun activities to help students discover how sound travels and how our ears pick it up.
- Grades: 6–8, 9–12
Start off your unit by looking at words that imitate the sounds they represent, such as hiss, rustle, growl, and chirp. This onomatopoeia enriches language, allowing us to capture sound in writing. After sharing some examples with students, ask, “What do these sound words mean to you? How do they make you feel? Excited? Annoyed? Happy?” Invite students to brainstorm as many sound words as they can think of. Encourage them to name sounds which are pleasant to them (and why), and which are unpleasant, and record these on a T-chart.
Hearing allows us to communicate with others and to navigate our world. Invite students to experience a heightened awareness of all the important sounds around them with a sound walk through several areas of your school, such as the hallway, cafeteria, library, and playground. Ask students to pay attention to all the different sounds they hear along the way. Then have members of the class compare their experiences. What different sounds did each person hear along your journey? Next, have pairs of students take turns observing the sounds in different areas of your classroom or school more closely. Ask one student in each pair — “the listener” — to close his or her eyes (or put on a blindfold) and describe all the sounds that he or she hears to the other student, who will record them. (You may want to monitor blindfolded students closely, or ask student pairs to choose a location and sit before the listener is blindfolded.) Encourage students to use rich, descriptive language in their observations. After everyone has been a listener, ask students to write short stories inspired by — and including — at least five of the different sounds they experienced.
Amp Up the Sound!
The loudness of sound, or its amplitude, is measured using the decibel. Small differences in amplitude (short sound waves) make quiet sounds, while large differences (tall sound waves) make loud sounds. Share with students the “How Loud Is That?” decibel chart, above, then try this fun demonstration. Cover a radio speaker with a sheet of paper, and sprinkle uncooked grains of rice on top. Turn the radio on and have students observe the rice. Next, crank up the music all the way — and watch out for flying rice! Based on what they observed, ask students to compare this experiment with the sound wave experiment above. Then ask: “What relationship exits between the loudness of sound and amplitude?” (The bigger the amplitude, the taller the sound waves, and, therefore, the more rice will jump off the paper.) To extend, tell students: “Some sounds have so much amplitude, they can damage our ears!” Have them further investigate decibel levels (starting with the links in "Sound Science Resources," above), then design hearing safety posters to share their findings with the class.