Lesson: Sound Environment Shapers
Contributed by: Integrated Teaching and Learning Program, College of Engineering, University of Colorado at Boulder
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Figure 1. Acoustical engineers help design auditoriums. click for copyright |
Summary |
Engineering Connection Category 1. Relating science concept to engineering |
Contents
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| Grade Level: 4 (3-5) | Lesson #: 3 of 3 |
Lesson Dependency  :None |
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| Keywords: acoustics, acoustical engineering, architectural engineering, barrier, environment, loud, movie, noise, quiet, sound, sound barrier, sound waves, theater, waves | |
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Related Curriculum
| subject areas |
Science and Technology |
| curricular units |
Sound |
| activities |
Form vs. Function |
Educational Standards :
- Colorado Science
- International Technology Education Association-ITEA STL Standards Technology
Pre-Req Knowledge (Return to Contents)
Students should understand that sound travels in waves and has a direction of travel. This lesson is ideal to accompany a science unit on sound or waves.
Learning Objectives (Return to Contents)
After this lesson, students should be able to:
- Describe the role of an acoustical engineer.
- List several common designed or "natural" acoustic features of a building.
- Use the science of sound waves to explain how designed sound environments work.
Introduction/Motivation (Return to Contents)
Can you imagine an office located next to loud city streets? Or, a classroom next to a gymnasium full of running students? Well, acoustical engineers sure can! In fact, part of the job of an acoustical engineer includes designing places for people to escape the loud noises of everyday life. Acoustical engineers design quiet sound environments, as well as sound environments for spaces that are supposed to be loud with sounds (auditoriums, concert halls and sports arenas, among others). They even design the sound barriers (walls) that you often see between a noisy highway and a quiet neighborhood (see Figure 2). These walls are part of noise mitigation efforts — simply referred to as noise control.
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Figure 2. A decorative sound wall separates a neighborhood from a highway, minimizing the noise to residents. click for copyright |
What kind of sound environment is a movie theater? (Answer: Quiet.) How about this classroom? Everyone be quiet for a few moments and listen. What do you hear? (Answer: Students may hear different things, such as feet shuffling or coughing, but overall it is [hopefully] quiet. Or, perhaps other sounds can be heard from nearby classrooms, the gym or parking lot.) How about a downtown street? (Answer: Loud.) Why do you suppose these different sound environments exist? People want a quiet environment to watch movies and conduct classes, but quiet is not important on a busy city street (unless you live next to it!). So people decide where quiet environments are important. How does this relate to acoustical engineers? What do they know how to do? (Answer: Acoustical engineers know how to create quiet spaces for people to enjoy.)
How do acoustical engineers create quiet spaces? To answer this question, think about what you have been learning (or already learned) in science class. How does sound travel? (Answer: Sound travels in waves.) When a sound wave strikes something hard, such as a concrete wall, is it absorbed or reflected? How about when sound waves strike soft surfaces? (Answer: Soft surfaces absorb sound waves, while hard surfaces reflect them, or bounce them back.) When sound waves are reflected, what is that called? (Answer: An echo.)
Let's compare a movie theater to a gymnasium. When a film is running, do you hear echoes? (Answer: No.) When you yell in a gymnasium, do you hear an echo? (Answer: Yes, usually.) What do you think explains this difference? How is the inside of a movie theater different from the inside of a gymnasium? (Answer: Theaters have thick, soft curtains, fabric-covered walls, angled/curved walls, and carpeting, while gyms usually have only hard surfaces [floors, windows, walls].) So what do engineers do to make the theater quiet inside? (Answer: They design the room with soft surfaces, such as curtains, fabrics, carpets and other materials that absorb sound instead of reflecting it. They may also make sure to muffle the sound from the film projector, heating/cooling system and doors, so they are not distracting to viewers.) So, to create quiet sound environment, acoustical engineers consider the reflection and absorption of sound waves.
Lesson Background & Concepts for Teachers (Return to Contents)
Acoustical engineers study the properties of sound and vibration in order to create controlled sound environments for people. Even though it is a specialized field, many acoustical engineering firms exist around the country and world. These engineers design sound walls to surround highways, barriers to alleviate the loud noise of airplanes and trains, and even super-quiet dishwashing machines. But, the most common work for acoustical engineering is in building design to reduce unwanted sounds (such as noise control in work places, homes, schools, theaters, auditoriums, sports arenas, airports, industry and road systems) and make useful sounds (such as for medical ultrasound equipment, sonar, and music and voice reproduction).
Architects seek consulting from acoustical engineers as they design spaces for a better sound environment. The sound environment, or acoustics, can be a major influence on whether or not the space as a whole is pleasant. Each building poses a unique challenge. Acoustical engineers provide solutions that not only create good acoustics but fit in with the overall architectural vision of the space.
The acoustical engineers at Arup
, an international engineering firm, created a sound lab in which they can simulate sound environments. To test their designs in the sound lab, they can listen to artificial performers in a concert hall, for example, before it is even built. This technology is made possible through the understanding of sound waves.
Vocabulary/Definitions (Return to Contents)
| Acoustics: | The study of sound; the characteristics of sound in an environment. |
| Echo: | A repetition of sound produced by the reflection of sound waves from a wall, mountain, or other obstructing surface. |
Associated Activities (Return to Contents)
- Form vs. Function - Students analyze the sound performance of different materials that represent wallpaper, thick curtains and sound-absorbing panels. They use what they learn to model and design the sound environment for a room.
Lesson Closure (Return to Contents)
Today, we learned about many different sound environments. Acoustical engineers shape these environments to meet the needs of the people using the spaces. They design various features of buildings to absorb more — or less — sound and to reflect the sounds in desired directions. In addition, they design areas that prevent loud street sounds from affecting buildings and homes.
To make their designs, acoustical engineers first learn how sound travels (in science classes, just like you). What happens to sound waves when they hit hard surfaces? (Answer: The sound waves are reflected, so the sound continues.) How about when sound waves strikes a soft surface? (Answer: Sound waves are absorbed by soft surfaces, so the sound does not continue.) Acoustical engineers use this information when designing sound environments to both enhance sound quality and reduce loud noises. (Show students the attached Example Acoustics Strategies in a University Classroom Building for more real-life examples.)
Attachments (Return to Contents)
Assessment (Return to Contents)
Pre-Lesson Assessment
Discussion Question: Solicit, integrate and summarize student responses to the question below. After listening to their answers, tell students that they will learn the correct answers during the lesson.
- Do you think building designers design some buildings to be quieter than others? Why would they do that? Give me some examples.
Post-Introduction Assessment
Diagramming Sound Movement: Draw Figure 3 on the board. Tell students that the arcs in the diagrams represent both source and reflecting sound waves in a room. Ask them to determine which room is most likely the gymnasium and which is a movie theater. (Answer: The gymnasium is the room on the left. The movie theater is the diagram on the right—the one with fewer reflecting "sound waves.")
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Figure 3. Sound waves are more absorbed in the surfaces and design of a theater (right) than in a gymnasium (left). click for copyright |
Lesson Summary Assessment
Look and Discuss: Ask students to discuss the following questions with a partner, then discuss as a class. (optional) Show students the attached Example Acoustics Strategies in a College Classroom Building for more real-life examples.
- Did the engineers and architects who designed our classroom care about the sound environment? How can we tell? What is one piece of evidence that shows acoustical engineering? (Possible answers: Sound-absorbing ceiling tiles, carpeting, thick walls, door jamb padding, placement away from noisy gym/playground/mechanical room/roads, reading nook away from main classroom space.)
- How could we make improvements to the sound environment of our room? (Possible answer: Create a reading corner with soft furniture, curtains and an area rug.)
Lesson Extension Activities (Return to Contents)
How does distance affect how sound travels? Have students think about designing a building that uses distance to quiet the sound environment. For example, if you were designing a school, where would you locate the various rooms to best take advantage of distance for purposes of improving the sound environment? (For example, not placing the gym or cafeteria next to the library.) Assign students to sketch a floor plan re-arrangement of the main spaces in their own school and explain the logic behind their suggested improvements.
Assign students to research high tech sound baffles or other devices and materials designed to reduce sound. In what situations might sound baffles be used? From what materials are sound baffles made? How do their designs absorb sound better than standard ceiling, wall and floor materials?
Can excess noise affect our health? Have students research the health effects of noise. Specifically, have them find out if noise contributes to hearing loss, blood pressure problems or sleep disturbances.
References (Return to Contents)
Arup Acoustics, "What we do," accessed July 24, 2008. http://www.arup.com/acoustics/whatwedo.cfm?pageid=4725
City of Chattanooga, Education, Arts & Culture: Performance Venues, Soldiers and Sailors Memorial Auditorium, accessed July 10, 2008. http://www.chattanooga.gov/2919_MemorialAuditorium.htm
Sullivan, John J. IV, US Dept. of Transportation, Federal Highway Administration. Public Roads, "Walls of Fame," Vol. 66, No. 6, May/June 2003, accessed July 10, 2008. http://www.tfhrc.gov/pubrds/03may/03.htm
Contributors
Michael Bendewald, Malinda Schaefer Zarske, Janet Yowell, Denise W. CarlsonCopyright
© 2008 by Regents of the University of Colorado. This digital library content was developed by the Integrated Teaching and Learning Program under National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.Supporting Program (Return to Contents)
Integrated Teaching and Learning Program, College of Engineering, University of Colorado at BoulderLast Modified: August 10, 2010