The Soundinator 1. Suggested Grade Range: 6-8. Approximate Time: 1 hour. State of California Content Standards:

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1 1 Students construct an apparatus to make sound using plastic cups, string, and hangers and investigate what is required to experience sound. Students will use the string to understand the relationship between the length of the string and the frequency of the sound. Suggested Grade Range: 6-8 Approximate Time: 1 hour State of California Content Standards: Science Content Standards Grade 6: Physical Sciences Students know energy can be carried from one place to another by heat flow or by waves, including water, light and sound waves, or by moving objects. Science Content Standards Grade 7: Investigation and Experimentation Scientific progress is made by asking meaningful questions and conducting careful investigations. As a basis for understanding this concept and addressing the content in the other three strands, students should develop their own questions and perform investigations. Students will: d. Construct scale models, maps, and appropriately labeled diagrams to communicate scientific knowledge (e.g., motion of Earth s plates and cell structure). Science Content Standards High School: Physics 4. Waves have characteristic properties that do not depend on the type of wave. As a basis for understanding this concept: a. Students know waves carry energy from one place to another. b. Students know how to identify transverse and longitudinal waves in mechanical media, such as springs and ropes, and on the earth (seismic waves). d. Students know sound is a longitudinal wave whose speed depends on the properties of the medium in which it propagates. Relevant National Content Standards: Next Generation Science Standards: Middle School Physical Science MS-PS4-1. Use mathematical representations to describe a simple model for waves that includes how the amplitude of a wave is related to the energy in a wave. [Clarification Statement: Emphasis is on describing waves with both qualitative and quantitative thinking.] [Assessment Boundary: Assessment does not include electromagnetic waves and is limited to standard repeating waves.] 1 An early version of this lesson was adapted and field-tested by Emily Sanders, Steven Richardt, Diane Jackson, Krissy Cuevas, Janie Oetken, Mireya Valenzuela, and Angela Lytle, participants in the California State University, Long Beach Foundational Level Mathematics/General Science Credential Program. 3-1

2 MS-PS4-2. Develop and use a model to describe that waves are reflected, absorbed, or transmitted through various materials. [Clarification Statement: Emphasis is on both light and mechanical waves. Examples of models could include drawings, simulations, and written descriptions.] [Assessment Boundary: Assessment is limited to qualitative applications pertaining to light and mechanical waves.] Lesson Content Objectives: Construct a device to experiment with creating and experiencing sound, called a Soundinator. Investigate and understand the necessary components for experiencing sound including the vibrating source, the medium, and the receiver. Draw and appropriately label a diagram of a Soundinator to indicate the vibrating source, the medium, and the receiver. Materials Needed: 1-2 feet of string per pair of students One metal hanger per pair of students Wire cutters (one or two per class) Optional o One plastic cup per pair of students with a hole punched in the bottom (do not use hard plastic cups because there needs to be some give in order to punch a hole without cracking the cup) o One paper clip per pair of students 3-2

3 Summary of Lesson Sequence Introduce the lesson by leading students in a discussion about their experience with sound. Guide students through building and experimenting with their sound experience apparatus, the Soundinator. Check for students understanding by asking the key questions provided while students are experimenting with the Soundinator. Allow students to practice their understanding of the three necessary components of sound experience by drawing and labeling a model of the Soundinator. To close the lesson, have students verbally describe other devices for which they can distinguish the vibrating source, medium, and receiver. Assumed Prior Knowledge Prior to this lesson students should have a basic understanding that energy can be carried from one place to another by sound waves. Classroom Set Up Students should work in groups of two or three to construct and experiment with their Soundinator. Lesson Description Introduction Lead students in a discussion of their different experiences with sound by asking: What experiences or situations have you been in when sound was different than normal? Under what contexts is sound decreased? Have you ever heard sounds under water? How is that different than hearing sounds in the air? How might we make different sounds from the same object? Does anyone in the class play an instrument? How do you create different sounds with that instrument? When students have had an opportunity to share their experiences and knowledge about sound, tell them: Today we will determine the necessary components to experience sound and we will be constructing a device with those components to experiment with. 3-3

4 Input and Model Demonstrate for students how to construct the Soundinator. There are two different versions of the Soundinator. Version 1 Version 2 1. Each pair needs a cup, a piece of string, a paper clip, and a metal hanger. 2. Tie one end of the string to the paper clip. 3. Thread the other end of the string through the hole punched in the cup so that the paper clip is inside of the cup with the string coming out through the bottom of the cup. 4. Tie the metal hanger to the string or simply hang it over the string while holding the other end of the string. 5. Two students may listen at the same time if a second cup is connected to the other end of the string as shown. 6. Tap the hanger and listen! 1. Each pair needs a cup, a piece of string and a metal hanger. 2. Tie the metal hanger to the string. 3. Hold the string up to your ear and press against the bone outside your ear. 4. Tap the hanger while holding the string to your ear. Note: the hanger does not need to be cut/bent as shown in the picture above. It could be a complete hanger connected to two cups. Be sure to use a metal hanger (not plastic or one with a cardboard cover). Guide Students Through Their Practice Explain that each student will have the opportunity to be a listener and also a sound producer. Allow students to choose who will be first as the listener. Have students hold the cup so that the hanger is dangling from the cup in mid-air. Next, tap the hanger and observe what kinds of sound they hear, including whether the sound is loud or soft. Next, the listener should stand up and hold the cup to their ear so that the string and hanger may hang freely without touching anything. The producer will then produce sound by gently tapping the hanger with their pencil on different places. The listener should not tell the producer what they hear. Students should switch roles after some time. After both students have had a chance to the listener, have them remove the cup and hold the string with the hanger attached to their ear or jawbone. The producer should gently tap the hanger. Students should switch roles so both get a chance to listen. 3-4

5 Check for Understanding Check for students understanding while they are experimenting by asking the following key questions: What parts of your Soundinator help you to experience sounds when you are the listener? What was the purpose of the hanger? What was the purpose of the string? What was the purpose of the cup (if using version 1)? Do you need all the different parts of the Soundinator to experience sounds? What else do you need to experience sound? You need a vibrating source, a medium, and a receiver to experience sound. Can you identify these components as parts of your Soundinator? When students have identified the three components necessary for experiencing sound, and are experiencing sounds with the string, ask the following key questions: Did it sound different if you hit different parts of the hanger? Did it sound differently with and without the cup? Do you think it would sound differently if you had a short piece of string versus a long piece of string? Do you think it would sound differently if you had a smaller or larger hanger, or only part of the hanger? Students should recognize that the size of the hanger makes a difference in terms of what they hear. The vibrating hanger is the source. (If students have not figured this out, encourage them to try listening to a whole hanger versus a hanger piece that has been cut off. You will need wire cutters to do this investigation.) Students should recognize that the length of string does not make a difference in terms of what they hear. The string is the medium that carries or transmits the wave. Independent Practice After students have had the opportunity to use the Soundinator and have verbally identified the vibrating source, medium and receiver components, instruct them to create a drawing of the Soundinator. Students should label their drawing with the components of the device and their functions (students will need to also draw a receiver, their ear, but might need explicit direction to do so). 3-5

6 Closure To close the lesson, challenge students to think of other sound experiencing devices for which they can identify the vibrating source, medium, or receiver. It might be worth revisiting the pre-lesson questions to see if students are able to apply their understanding of sound. At this point, ask students about sound in space (or a vacuum). Can astronauts hear sounds in space? What is different in space than on Earth that changes how we experience sound? What does this tell us about the accuracy of movies or television shows that take place in outer space? (It is quiet in space. There is no atmosphere, so no medium to vibrate and carry the sound.) Suggestions for Differentiation and Extension Sound Bite: Have students slide a straw over a pencil or wooden dowel and place one end on a wall or table. Ask students to bite on the pencil or dowel while plugging their ears and observe what they hear without using their ears. (The straw is for sanitary purposes, it is not a required element.) PHET Sound Simulation: Visit the website and let students experience the ranges of frequencies which they are able to hear by selecting the Listen to a Single Source page. Enable the audio on the program to hear the sounds being generated and adjust the frequency and amplitude. Discuss the relationship between the frequency and wavelength and how those concepts are related to the length of the string from their Soundinator and the sounds they experienced. Visit the Listen with Varying Air Pressure page from the same PHET website to allow students to hear how the volume decreases and eventually disappears as air pressure decreases to a vacuous state. Straw Kazoo: Visit one of the websites below to get directions on how to make a kazoo from a straw. The pitch of the kazoo will change as the length of the straw changes. The straw is vibrating as the students blow through it. If the straw is cut the length of straw which vibrates is shorter. A shorter wavelength means higher frequency or pitch. You can see (and hear) the kazoo in action at