Overview

In this inquiry lab activity, students use technology including a free virtual oscilloscope to determine the links between the wave characteristics of sound waves and how people perceive sound.  They will discover the connection between amplitude and volume of a wave, and the connection between the frequency of a wave and the pitch that people here. 

Context for Use

I use this lab after introducing students to the characteristics and parts of transverse and compression/longitudinal waves.  We use this lab at the beginning of our unit on sound.  Students tend to remember the connection between sound wave characteristics and the sound that we hear when they discover them through inquiry, rather than having me tell them the connections.  Also, this is LOTS of fun.  I have students who play musical instruments bring them to class on the day that we do this lab.  It is a great way to connect science class to their lives outside of class.  Also, it helps me develop strong relationships with my students because I get to learn a little more about each person and the instruments that they play.  I have students work in partners using one device to do the lab.

Materials

Chromebooks or other computers with internet access, microphones, and speakers

Instruments- those brought in by students

Headphones/earbuds- I have students wear these when using the online piano so that they can hear the notes without disturbing others in class

Links embedded in the lab:

     Chrome Music Lab:

     https://musiclab.chromeexperiments.com/Sound-Waves

      Trouble-shooting: If the high frequency waves stop working, have students refresh the page.  This usually fixes any issues.

Virtual Oscilloscope: 

 https://academo.org/demos/virtual-oscilloscope/

Trouble-shooting: Be sure that students allow access to the microphone on their devices when loading this page so that it will pick up the sounds from the microphone.

Student Activity Sheet

 For a formatted version of the handout, see the links here: 

Student Activity Sheet- Google Doc

An accessible version of the worksheet is also available below.

Visualizing Sound Waves Lab

Part 1:

Directions: 

• Visit the following website.

https://musiclab.chromeexperiments.com/Sound-Waves

• Experiment with the keyboard and make observations of the sound waves produced when you play different notes on the keyboard.

• Answer the questions that follow. (Use the zoomed-out view here)

Questions: 

1. What type of waves are being produced by the piano (transverse/longitudinal)?

2. Draw the wave produced by a high pitch sound. Label the compressions and rarefactions.

3. 

3. Draw the wave produced by a low- pitch sound. Label the compressions and rarefactions.

4. Compare the waves of a high pitch sound and a low pitch sound in terms of:

Zoom in on the waves to see the transverse wave “translation”

5) Based on the table on the previous page, what factor of the wave seems to affect pitch?  Explain how you can tell based on your data.

6) Why do you think people “translate” sound waves from compression waves to transverse waves?

Part 2: 

Directions: 

• Visit the following website:

https://academo.org/demos/virtual-oscilloscope/

 Give the website permission to access the microphone of the chromebook.

•  Try experimenting with making high, low, soft, loud, and other sounds. Try making the sounds by using an instrument or by whistling.

•  See how each wave looks when you click on “Freeze live input” button.

• Complete the graphs and questions about the waves that you make.

7) Draw the waves that you make: 

         High-pitch sound                   Low-pitch sound

8) Compare and contrast the characteristics of the two waves.

9) Loud Sound Soft Sound

10) Compare and contrast the characteristics of the two waves.

11) Produce a sound with a musical instrument or by whistling.  Try to get a single tone that produces a clear wave shape.

Draw the wave that you produce and label the following:

• Amplitude

• Wavelength

• Trough

• Crest

12) Try working with another person to make more than one noise as a time.  How does this affect the waves?

Draw what you see:

13) Extension: 

How do noise canceling headphones work?