Minds On
Sound all around you
This learning activity highlights people, places, or innovations that relate directly to the province of Ontario. Enjoy the exploration!
Energy is all around. People see light energy and feel heat energy, but what energy do they hear?
The answer is sound.
A person speaking, a dump truck rumbling down the street, and music blasting out of a phone are all examples of energy people can hear: sound.
Sound seems to come in all shapes and sizes: loud, quiet, high, and low. Sounds can be joined together to make music, or be separate, like a door banging shut. Most sounds are heard, but some sounds can be felt. Vibrations from loud sounds can be felt when a hand is placed on a music speaker, or felt through the ground when a train rumbles by.
Student Success
Think!
Make a list of some of the sounds you might experience during a typical school day. Record your answers on paper, digitally, or orally. If possible, work with a partner.
If you want, you can use a recording device to record some of the sounds you discover. Think about the quality of the sound.
- Is it loud?
- Is it high pitched?
- Is it clear or muffled?
- Does it have a purpose?
Create a chart with headings to organize your ideas. Your headings might be the source of the sound, quality, loudness, etc.
Note to teachers: See your teacher guide for collaboration tools, ideas and suggestions.
Action
Properties of sound
Sound moves through the air and other matter in waves, much like waves through water.
Sound waves are vibrations.
A vibration is the fast back-and-forth movement of air. The vibration pushes against the air and travels through matter as a compression wave. If there is no air, or water, or matter for the wave to travel through, there would be no sound. Since space is a vacuum, there is no sound in space!
There are three people on the left and the right side of a siren. On the left, there is an astronaut in space. On the right, there is one person on land and one person scuba diving under water. The siren emits sound. The sound vibrations are able to travel through air and water to reach the people on land and scuba diving. There are no sound vibrations traveling through the vacuum of space to reach the astronaut.
How do you think sound vibrations can be made visible?
Let’s check out the following video where a scientist will create a vibration by knocking a tuning fork on a counter.
What do you predict will happen when the vibrating tuning fork is placed in water?
My prediction
Now that you have made your prediction, check out the following clip from the Science North video entitled “Sound Vibrations”.
What happened when the tuning fork was placed in the water? In your own words and in a method of your choice, compare your prediction to what happened.
Press ‘Hint’ to check which option from the prediction checklist was correct
The tuning fork will make the water move. When a vibrating object creates a sound wave, it can be heard as a sound in the right kind of medium. As we explored in the previous video, when a sound wave enters air, it can be heard as a sound!
How can a sound wave can be recorded as a drawing for sounds that are high pitch and low pitch? Check out the following clip from the video entitled “Sound Vibrations” to learn more.
Let’s explore pitch and frequency!
Pitch is the word we use to describe whether a sound is high or low. Sounds with a high pitch are made by objects that are vibrating quickly. Sounds with a low pitch are made by objects that are vibrating slowly.
A sound can be high pitched or low pitched. A high pitched sound has a higher frequency sound wave.
Frequency is the word we use to describe how fast or slow a sound wave is moving. Sounds with a high frequency are made by objects that are vibrating quickly and have a high pitch. Sounds with a low frequency are made by objects that are vibrating slowly and have a low pitch.
For example, guitars have several strings of varying diameters, so when they are struck or strummed, they make different pitches. Each string vibrates at a different rate, or frequency. That’s one way that guitar can make different sounds!
High pitched sounds have a higher frequency, which means the waves are close together.
Low pitched sounds have a lower frequency, and have waves that are further apart.
In the following Matching activity, choose the sound wave frequency that matches the pitch.
Sound can be modified
If the pitch of a sound is determined by the frequency of the sound waves, the volume of sound is determined by the size of the waves. This volume is known as amplitude. A sound is perceived as louder when it has a large amplitude. A sound is perceived as quieter when it has a smaller amplitude.
The larger the sound wave, or amplitude, the louder the sound.
The smaller the sound wave, or amplitude, the quieter the sound.
When a sound is changing, such as getting louder or getting quieter, it is being modified. A modification is when something is changing. When the pitch of a sound is changing, it is being modified!
Pause and Reflect
Sound volume
How might you describe a change in sound volume using the following terms (in your own words):
- Waves
- Pitch
- Amplitude
- Modification/modified
Record your thinking on paper, digitally, as an audio recording, or in any other method of your choice.
Sound can be reflected
Have you ever heard an echo? That’s an example of sound being reflected. Sound waves travel in straight lines and will bounce off of surfaces. Try the following sound reflection investigation.
Before beginning your investigation, check out this video to learn about the steps of the Scientific Research Process.
Let’s try a sound reflection investigation!
Press the following tabs to follow the steps for your investigation.
Start by finding the following materials.
You’ll need:
- a wall or small board
- two cardboard tubes about 10cm in diameter. You can also make your own tubes out of rolled up paper.
- something that’ll make noise, like a phone timer or a kitchen timer
2 cardboard tubes lying on a table in front of a board. There is a timer at the end of one tube. Your ear goes at the end of the other. The angles between the 2 tubes and the walls must be the same.
Lay the two cardboard tubes on a table in front of the wall. You can also hold the two tubes against the board.
Put the timer at the end of one tube and your ear against the open end of the other. Move the two tubes until they are the same angle from the board.
When the angles between the two tubes and the wall or board are the same, you should hear the timer.
Great work at investigating sound reflections!
Sounds can be absorbed
Soundproof rooms have walls made of a specific kind of material that absorbs sound waves. Examine the photo and note how the foamy looking material is not smooth; it is filled with angles. As the sound waves from the singer bounce around the room, they are absorbed by the material on the walls.
Let’s try a sound absorption investigation by creating a soundproof box!
Press the following tabs to follow the steps for your investigation.
Start by finding the following materials.
You’ll need:
- a box – a shoe box is a good start
- egg cartons
- towels or rags
- tape
- a kitchen timer, a radio, or anything that can make noise
Use tape to line the inside of your box with the part of the egg carton that holds the egg. It’s best if you’re able to line the entire inside of the box.
Use the towels to fill any gaps.
Place the timer or radio inside of the box and turn it on so you can hear the noise.
Close the lid of the box and see how well your soundproof box works!
The sound is absorbed by the soft egg carton and towels. The uneven surface of the egg carton reflects the sound at lots of angles, weakening it.
Check your knowledge of the properties of sound. For each sentence, select the missing word from the drop-down menu.
Consolidation
All about sound!
Pause and Reflect
Properties of sound
You’ve had the opportunity to interact with properties of sound.
- Which properties surprised you?
- Which ones did you find interesting?
- Which would you like to explore more?
Record your reflections on paper, digitally, or orally.
Reflection
As you read through these descriptions, which sentence best describes how you are feeling about your understanding of this learning activity? Press the button that is beside this sentence.
I feel…
Now, record your ideas using a voice recorder, speech-to-text, or writing tool.