Think like an Acoustical Engineer! Pt.3

Course Content

Lesson 4 of 4

02h : 0m

K - 1st

Engineer

Ingenia Context [5 min]

Script: Welcome to the Ingenia History Museum where we are visiting an exhibit all about the history of communication. Right over here, we can see the history of the telephone: a device used for transmitting sounds over long distances. Wow, it looks like the first string phone was invented in 1665 and the first telephone was invented in 1876 by Alexander Graham Bell. Let’s take a look at the evolution of the telephone and how it has changed over the years:

Watch and discuss: Evolution of the Telephone (https://www.inspire.education/) (note: teachers can pause this short video slideshow as needed to look at each phone and discuss further if desired)

Today, we will be exploring how sounds are transmitted and we will even be making our own simple string phones like we saw in the video! Are you ready to get started?

ENGAGE

Transmitting Sound [15 min]

Materials: one tuning fork and a string that is approximately 1.5 meters long for each small group of students

Opening Discussion [5 min]: Start an opening discussion about sound and how sound travels using one or more of the following prompts:

How does sound travel? Sound waves travel as vibrations.
What is needed for sound to travel? A source – where the sound is made. A medium – something for the sound to travel through. A receiver – something to detect the sound.

Tuning Fork Exploration [5 min]: We know that sounds need a source, a medium, and a receiver to travel. Let’s explore this a bit more using a tuning fork and string:

PART 1

Break students into small groups and provide each group with one tuning fork and a string that is approximately 1.5 meters long.
Have students tap the tuning fork on their desk or chair to sense the vibrations by positioning it near their ear to listen to the subsequent sound generated through these vibrations. Try holding the tuning fork in different places and observe what happens

PART 2

One of the students in each group should wrap each end of the string onto the forefingers of each of their hands, and then place their fingers in their ears.
Balance or tie the tuning fork on the string. Students should hit the tuning fork against a hard surface.
Think about the following:

What is happening and why are you hearing this sound?
Why is it different from the sound you get just by hitting the fork without any string?

Debrief [5 min]: Debrief on this activity using one or more of the following prompts:

What did you observe in this activity? Answers will vary. Students may have observed that when the tuning fork is connected to a string, the vibrations are transmitted from the fork to the string and to the ear drums through the forefingers.
In this activity, what was the source, medium, and receiver? The string is acting as a medium to transmit the sound or the vibrations from the fork (source) to the ear (receiver).
What is the source, medium, and receiver when we are talking like right now? In most other cases (e.g., when we speak or play music), the air acts as the medium to transmit the sound from the source to our eardrums.

‍Note:The discussions and tuning fork exploration is adapted from this inquiry article from Science and Children. View this pdf for helpful images of the tuning fork activity. A more engaging way to teach the science of sound

EXPLORE

Engineer a String Phone [20 min]

Materials: 2 paper cups already prepared with a hole poked into the bottom of each one and string (e.g., kite string or fishing line) per each partnership of 2 students

Script [5 mins]: Today we are going to engineer a basic string phone in order to explore sound transmission, just like in the video we just watched. Are you ready to get started?

String Phone [10 mins]

Break students into groups of 2. Provide each group with a long piece of string and two cups with holes in the bottom.
Have students thread the string through each cup and tie knots at each end to stop it pulling through the cup (alternatively you can use a paper clip, washer or similar small object to hold the string in place). If you wish to save time, teachers can pre-assemble the phones and simply have students test them.
Move into position with each student holding the cups at a distance that makes the string tight.
Have one person talk into the cup while the other puts the cup to their ear and listens. Can you hear each other? Now, try saying the name thing in the same volume and from the same distance to your partner without the phone. Can you still hear each other?
If time permits, explore with different lengths of strings, standing with the string loose versus tight, and other variations. What is the best setup to hear each other clearly?

Discuss and Debrief [5 mins]: Come back together as a class and discuss one or more of the following prompts:

How does your string phone work? Speaking into the cup creates sound waves which are converted into vibrations at the bottom of the cup.
How is sound transmitted through the string phones? The vibrations travel along the string and are converted back into sound waves at the other end so your friend can hear what you said.
Why can you hear better from a distance through the string phones? Sound travels through the air but it travels even better through solids such as your cup and string, allowing you to hear sounds that might be too far away when traveling through the air.

Note: This string phone activity is adapted and modified from this Science Kids activity:

Make a String Phone - Fun Science Projects for Kids

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Exploring Materials to Transmit Sound [20 min]

Materials: Tuning forks and different types of string materials (e.g., yarn, thread, fishing line, rope, plastic lacing, etc.) for each student

Exploration [15 mins]: Explain to students they will be using the tuning forks again. This time, they can try different types of string materials in order to explore which string materials work well to transmit sound.

Discuss and Debrief [5 mins]: Ask students to share their observations. Create a class list of the string materials that work best to transmit sound and the materials that work the worst to transmit sounds.

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Engineer A Sound Transmission Technology [45 mins]

Students work with a partner to use what they’ve learned about sound, vibrations, and string phones to engineer a new technology that can transmit sound across a distance.

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Materials: per student	Instructions
- Various string materials like: string, twine, wire, plastic lacing, fishing line, etc. - Various cup materials like: cardboard boxes, yogurt cups, paper cups, plastic cups, etc. - Optional: access to tape or rubber bands to connect materials together - Optional: child safe scissors	1. Your sound transmission technology needs to transmit sound at least 4 feet and use a minimum of 3 different materials. 2. Select a string material/s based on the string material exploration. 3. Select a cup material/s. 4. Connect your string and cups and test them with your partner. 5. Does your technology transmit sound across a distance? If not, what can you change?

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5 min Script: We’ve been exploring how sound transmits through different materials. You’ll now use what you learned from exploring the string phones and various string materials to design your own sound transmission technology. This technology will work like a string phone, but with a partner you’ll decide together on which materials to use for the string and cups. You can combine materials in different ways and explore how it changes the technology. Your sound transmission technology needs to: transmit sound across at least 4 feet and use at least 3 different materials.

35 min Assign student pairs and dismiss students to begin engineering a sound transmission technology. Circulate as students engineer to support the process and ask:

How are you engineering a sound transmission technology?
Why did you select these materials?
How are you working together to engineer this technology?

5 min Gather students together with their sound transmission technologies. Lead a group discussion:

How did you engineer a sound transmission technology?
Why did you select those materials?
How did you work together to engineer this technology?
What would you change about your technology if you had more time?

Sound Transmission Technology Showcase [10 mins]

Have students walk around to observe demonstrations of each person’s technologies and ask questions. Encourage students to ask questions about the process (e.g., how the technology was designed or created) and about the final product itself (e.g., what materials were used and why).

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Homework [5 min]:

Students can bring home the sound transmission technologies they created to demonstrate for their family. Encourage parents and caregivers to ask students one or more of the following prompts:

Tell me about what you created.
Can you show me how it works?
Can you point out the different materials you used?
What were some of your challenges when creating this?

If students would like to change or improve on their sound transmission technologies at home, encourage caregivers to provide basic craft materials for students to continue improving their designs.

Materials

- One tuning fork and a string that is approximately 1.5 meters long for each small group of students

- 2 paper cups already prepared with a hole poked into the bottom of each one and string (e.g., kite string or fishing line) per each partnership of 2 students

- Various string materials like: string, twine, wire, plastic lacing, fishing line, etc.

- Various cup materials like: cardboard boxes, yogurt cups, paper cups, plastic cups, etc.

- Optional: access to tape or rubber bands to connect materials together

- Optional: child safe scissors