Lesson 1: Follow the Sounds
Time Required: One 40-minute class period
Materials: Sound Off! student worksheet, earplugs (optional)
This lesson helps students explore sounds and the origins of sounds through a listening experiment.
1. Distribute the Sound Off! student worksheet. Students will work in pairs to complete this activity. If possible, each pair should find a relatively quiet corner of the classroom or hallway in which to work. (You may wish to have student pairs take turns completing the activity to minimize noise distractions.)
2. To begin, explain that students will take turns using earplugs (or their hands) to muffle their hearing. Students will follow the chart on the worksheet to cover one ear at a time, then both ears together, and then leave both ears uncovered. Student A will close his or her eyes and listen while Student B moves somewhere in the vicinity and creates a sound. (Sounds may include whistles, spoken or whispered words, clapping hands, snapping fingers, etc.)
3. Following the chart, Student A will fill in information about each sound and its location. Student B should also record this information to compare with Student A’s worksheet later. After filling in the chart, the students should switch places and repeat the exercise.
4. Have a class discussion about the students’ findings. Ask: How did muffled hearing affect your ability to judge a sound and its location? How did covering one ear compare to having both or none covered?
5. Explain: Your ears are remarkable organs. They can detect the low rumble of distant thunder, the high-pitched chirps of birds, and the complex sounds of human speech. And if you listen carefully, your ears can tell your brain where the faintest rustle or quietest whisper is coming from. Ask students to discuss the results of the activity.
6. Elaborate: Sounds are made of waves. Your ears are sophisticated organs that collect sound waves, process them, and send sound signals to the brain. The brain compares information coming from both ears. For example, if a sound occurs on your right, it will arrive in your right ear a fraction of a second sooner than it reaches your left ear. It will sound a little louder to your right ear, too. Although you might not notice these tiny differences from ear to ear, they allow your brain to determine the location of the sounds you hear.