In Ohio, sound is part of the science curriculum in Kindergarten, Grade 5 and Grade 7. In each case the students are supposed to explore how changes to sound waves can affect the pitch and loudness of the sound. The Ohio model curriculum encourages teachers to use virtual tools to visualize or simulate these concepts.
A great tool to do this is the free Chrome Web App called TwistedWave. This is a free online tool that lets you record sound, play it back, see a live visualization of the sound waves, edit the sound (pitch, amplitude, etc), and see the effect those changes have.
See below for a video tutorial showing how to use this web app, then read through the rest of the blog post for more details on the tool as well as the Ohio science standards addressed.
Video Tutorial (11 minutes)
TwistedWave can be installed through the Chrome Web Store at https://chrome.google.com/webstore. The direct link to install the web app is here: Chrome Web Store link
With the TwistedWave editor open, you can do the following:
- Click the red record button to record from your mic
- Click the play button to play back your recording
- Use the Zoom In and Zoom Out buttons, or the scroll wheel on your mouse, to zoom in on the sound waves
- Click and drag to select a portion of your recording
- Click “Effects” and “Amplify” to increase or decrease the loudness of the selected part of the recording
- Click “Effects” and “Change Pitch and Speed” to increase or decrease the frequency of the selected part of the recording
- Click “File” and “Send to Google Drive” to save your recording to your Drive
In the science classroom you can use TwistedWave as a great way to visualize sound, pitch, and amplitude.
- For one option, you could record a variety of sounds with different pitches or volumes, and then have the students compare their sound waves to see what is different between them.
- Or for a second option, you could record one sound, and then use the editing tools in TwistedWave to change the pitch up and down, and change the amplitude up and down, allowing the students to see the change to the sound wave, as well as to hear the results those changes make.
Either way this can be a fun, engaging, and practical way to learn about and experiment with sound waves.
Ohio Science Standards
Some objects and materials can be made to vibrate to produce sound.
Sound is produced by touching, blowing or tapping objects. The sounds that are produced vary depending on the properties of objects. Sound is produced when objects vibrate.
Sound can be made in many ways. Objects like cymbals, the tabletop or drums can be tapped to produce sound. Objects like a rubber band or a guitar string can be plucked to produce sound. Objects like a bottle or a trumpet can be blown into to produce sound. A wide variety of sounds can be made with the same object (e.g., a plastic bottle could be tapped or blown into). The connection between sound energy and the vibration of an object must be made. Vibrations can be made visible when water splashes from a cymbal or triangle placed in water or rice vibrates on the top of a banging drum. The concepts of pitch (low vs. high notes) and loudness are introduced. The pitch of sound can be changed by changing how fast an object vibrates. Objects that vibrate slowly produce low pitches; objects that vibrate quickly produce high pitches. Sound must be experienced, investigated and explored through observations and experimentation. Standard, virtual and student-constructed instruments must be used to explore sound.
Investigate how the stretch of plucked rubber bands affects the sound
Use questions to investigate and experiment pitch. Ask: How are pitch (higher/lower notes) and vibration changed as a rubber band is stretched further and further?
Use graphics (e.g., digital photographs, virtually composed graphics) to represent the observations from the experiment. Compare the notes made from rubber bands that are stretched different amounts.
Compare the relative speed of vibration (faster/slower) to the pitch (higher/lower notes) of the sound produced.
Sound is produced by vibrating objects and requires a medium through which to travel. The rate of vibration is related to the pitch of the sound.
Pitch can be changed by changing how fast an object vibrates. Objects that vibrate slowly produce low pitches; objects that vibrate quickly produce high pitches. Audible sound can only be detected within a certain range of pitches. Sound must travel through a material (medium) to move from one place to another. This medium may be a solid, liquid or gas. Sound travels at different speeds through different media. Once sound is produced, it travels outward in all directions until it reaches a different medium. When it encounters this new medium, the sound can continue traveling through the new medium, become absorbed by the new medium, bounce back into the original medium (reflected) or engage in some combination of these possibilities.
Technology and virtual simulations and models can help demonstrate movement of light and sound. Experimentation, testing and investigation (3-D or virtual) are essential components of learning about light and sound properties
Explore properties of light and sound. Recall that increasing the rate of vibration can increase the pitch of a sound.
Waves can be described by their speed, wavelength, amplitude and frequency. The energy of a mechanical wave depends upon the material, decreases with increasing wavelength, and increases with amplitude. The pitch of a sound wave increases with the frequency and the loudness increases with amplitude.
For grade 7, investigation and experiments (3-D and virtual) must be used to connect energy transfer and waves to the natural world. Real data must be used, such as oceanic or seismic wave data or light and sound wave data.
Post by Eric Curts. Bring me to your school, organization, or conference with over 50 PD sessions to choose from. Connect with me on Twitter at twitter.com/ericcurts and on Google+ at plus.google.com/+EricCurts1