Can You Hear Me Now?

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SWBAT test different materials to determine which is the best suited to absorb sound.

Big Idea

Material engineers learn about sound waves as they explore the properties of different materials that do the best job of absorbing sound.

NGSS Connections and Class Preparation

30 minutes

NGSS Standards

2-PS1-2  Analyze data obtained from testing different materials to determine which materials have the properties that are best suited for an intended purpose. 

Students test materials to see which is the best material to use for sound insulation.

Science Practices

- Planning and Carrying Out Investigations (SP 3)

Students identify the variable to be tested and the variables that should remain the same for each test. 

- Analyzing and Interpreting Data (SP 4)

Students use a decibel chart to help them determine how well their sound insulation is working, or if available, an app that measures dB.

Here is a link to compare dB for different activities, could be used as reference. There are free dB measurement apps to use on the iPad. I will be using Decibel to the 10th.

- Constructing Explanations and Designing Solutions (SP 6)

Students review their data to explain which material makes the best sound insulation. This information is used to build a class bar graph. Subsequently students make conclusions bout the material's attributes that make it suited for soundproofing

Lesson Preparation

Cue the sound power point

Collect materials to test for sound proofing; possible items:

felt, cotton balls, packing peanuts, bubble wrap, newspaper

Make a chart to identify material with label

The teams choose 4 materials to test. I provided a number of items for possible insulation materials so teams would be encouraged to discuss which materials would work the best. By providing the students with choice encourages them to think for themselves and defend their reasons.

Collect cardboard tubes; one tube per team

If possible have an app or device that can measure dB

Copy 'Sound Insulation Lab'; one per team

Make teams

Question for the Day

5 minutes

Science starts with a question, usually written on the board. This allows time for students to consider today's topic before the lesson has officially begun. I have established this routine with the kiddos to keep transition time short and effective and redirect student's attention back to content while allowing time for focused peer interaction.

Question for the Day: When would we want to block or muffle sound?

Our school is by a busy urban airport, so sound quality can be an issue. I wanted to choose a situation that students could connect to.

Students turn to share ideas with their neighbors. When students have signaled that they are finished with their discussion by turning to face me, I invite volunteers to share what their neighbor said.

This encourages active listening when partners share and when volunteers repeat what their partner said.

I write answers on the board.

"Since our community is close to an airport, when builders build homes, they want to make sure that they use materials that will help block out noise of jets engines. These materials can be soundproofing insulations. Do you remember what we call a scientist that looks at materials to test for certain properties? Yes, a materials engineer!"

"As material engineers, you will work in teams of 4, to select and test materials to 'hear' which insulation blocks sound the best."

I use the random sorter to make groups. Then I direct students to sit with their team.

This helps me get a visual on who is in each group, in case I see some combination of students would not promote a productive lab. 


One Variable at a Time Please

15 minutes

For this next section I use the Power Point - sound insulation to guide the discussion.

Slides 1- 3 Define Sound Insulation

"Material Engineers, what is our question that we want to test and answer? Right, what material would be the best sound insulation."

I introduce 'insulation' to help develop students' academic language.

Slide 4 Sound Insulation Materials

"Remember when you built your erosion models we discussed that we would need to keep the slope, water and amount of soil the same so that we would only be testing for the one variable, the erosion design?

"What is the variable we want to test for? Right the best material that will insulate sound. Testing different materials is the only part of the test you will change.

"Let's make a list of materials you could test. I have gathered some materials you could use on this table, but if you have ideas for other materials that we can find in the classroom, please share those ideas too."

I use this opportunity to name the materials so that all students are familiar with the material names. I also want to give students an opportunity to include their ideas of materials.

"The materials you choose to test for sound isolation, is the only part of your test that will change."

Slide 5 Variables to Remain the Same

"Let's think about what needs to stay the same each time you test, so you are testing the materials. Please turn to your table partner and discuss your thoughts about what will have to be the same for each test."

I walk around the room to listen to student conversations. I note which students mention that the sound volume will need to be the same for each test so that I can call on them to share with the class.

If the following variables are not mentioned by the students, through a guided discussion, the following variables are reviewed:

The variables are animated on the slide when I tap on the screen.

- distance between sound produced and received; Students use a cardboard tube to keep the distance consistent

- volume; Students discuss that the volume needs to be the same for each test and that the same noise/sentence should be said by the same person

- measuring the volume at the other end of the tube; We discuss that the same person needs to be the listener and use the decibel chart to compare how loud the sound is.

Slide 6 Procedure

I show students how they will place the material in the tube. (show video). Then review the following with the slide:

Volume: Select one person from your team to say the same sentence in a 'presenters' voice. The same person speaks for each material test.

The students and I discuss the pros and cons of telling the sentence to the listener. I let the teams decide whether or not the listener will know the sentence.

Distance: Use the cardboard tube to place material in. Person speaks into the tube.

Measure Volume: (this will be subjective, unless I can use a dB reader, a possible app for the iPad) Select one person from your team to listen to the speaker and 'measure' the sound. The same person listens for each test.

Afterward the procedure for testing sound insulation materials are summarized. I invite students to discuss the procedure with their team.

Slide 7 Chart to Compare Decibels to Common Sounds

"Volume is how loud sound is, which is measured in decibels. This is a chart that shows you the decibel rating for some common sounds. After the listener listens to the sound, you will use the chart to help you decide what decibel score you will write for the material."

"You will write your observations and your best guess decibel score, Your observations could include a description of what you heard, maybe you only heard some of the words. All of the words...

I review some of the sounds with the kiddos.

I found a decibel app for the class ipads which I chose to use instead of the decibel chart  Slide 7 was a great segue to decibel readings on the app.

The Sound Lab

30 minutes

I pass out the lab form students will use. It includes a space for them to write their hypothesis and observations.

I also pass out a cardboard tube to each group so they can explore how their voices sound without any insulation.

While teams are exploring the properties of sound and the tube, I lay out the testing materials on the back table.

I provide teams with samples of each material to help them decide which materials they will test.

I signal for students' attention, "After you have selected and written 4 materials you want to test, choose one person from your team to pick up the first material you will test fromthe back table.

"Teams will test a material, write your data and observations and then return the material to the back table. The material person will pick up the material you want to test next."

While students are testing I ask teams about their results. I ask them about their procedures, if the results would be different if the materials were placed in the tube in another way? What do they think is happening to the sound waves?

10 minutes before science is over, I signal students' attention and direct them to write their conclusion based on the data they have. I remind them to use our 'anchor conclusion chart' to help them write their conclusion. Together we discuss the lab topics that would be addressed with the conclusion anchor chart.

I will be collecting the lab forms to check that observations were written and that the conclusion is based on their observations.


Best Sound Insulation Bar Graph

10 minutes

"Once your team has finished writing their conclusion and turned it in, please take a seat on the rug. You will help me make a bar graph to show which material your team determined was the best sound insulator."

I intended for the students to make a bar graph, but they needed the entire science time to complete their.

As in previous lessons, students could write their results and conclusions during the language arts time, which allows more time to review and discuss results. See the reflection for this section.

I have made a bar graph on tag board. Students use post-its to indicate which material their team tested to be the best sound insulator. We discuss what we can learn from the bar graph and students thoughts on the lab.

Instead of the bar graph, the next time we meet for science, I tallied the top insulating materials based on the teams' results. This information and discussion is used to develop a class conclusion for the lab.

Creating the bar graph with my students provides an opportunity for me to show them how scientists can summarize their notes. It provides a visual way for us to compare which materials were the best insulators.

The post-its allow students to participate with building the bar graph without time needed to color in another section of the bar. 

My kiddos will be moving into a graphing unit in math. This activity provides a way for me to front load some of the learning. 

Lab work is collected.

I will review lab papers for completeness and that their conclusions address the bullet points on the 'conclusion anchor chart.'