SOUND
INVESTIGATION # 1
Literature Resources:
SOUND INTRO...
This module provides experiences that help students develop an understanding of how to observe and manipulate sound. They explore these dimensions of the natural world using simple tools and musical instruments.
Students learn that sound comes from vibrating objects. They explore how to change sound volume and pitch, and develop simple models for how sound travels from a source to a receiver.
Throughout the Sound and Light Module, students engage in science and engineering practices by collecting data and designing and using tools to solve problems and answer questions. Students gain experiences that contribute to their understanding of the crosscutting concepts: patterns; cause and effect; and systems and system models.
INVESTIGATION 1 — Sound and Vibrations
Investigation 1: Sound and Vibrations:
Students explore the production of sound with a table fiddle, tuning forks, a tone generator, cups, sticks, and rubber bands. Students look for vibrations at the sound source and come up with words to describe different sounds. They learn how to discriminate between different kinds of sounds and what information sounds convey. Students find out about sounds that different animals make.
What Causes Sound?
The environment is filled with natural and human-made sounds. Some sounds are made intentionally, others accidentally. Regardless of where they come from, many of these sounds convey messages in a code that we have learned to interpret as information.
A ring tone sends us reaching for the phone; not any tone, but the particular tone that we’ve learned to recognize as the one signaling a call to our phone. Similarly, the sound made by a glass of milk falling to the floor signals a mess, and the sound of a siren alerts us to an emergency vehicle in the vicinity. In each case, we can discriminate a sound in our environment and identify it as being different from all other sounds. Some sounds are loud, others are soft. We observe and comparesounds and make judgements about them based on by their properties.
Sounds that are loud or that sound for a long time are usually easy to identify. Sounds that we hear on a regular basis are easy to identify. Through experience, we have learned to match sounds to ideas and events: a dog barking, the sound of a saw cutting wood, and the sound of the school bell ringing.
If we go outdoors and listen carefully, we can hear a variety of sounds in the local environment. Some sounds are loud, some are soft; some have a high pitch and some have a low pitch. All the sounds we hear are the result of something vibrating. The challenge is to find the source of the sound. We can use tools, such as a megaphone, to focus the sound from the source as it travels to the receiver, our ear. Our ears are sound receivers.
PART # 1: Sound and Vibrations
We are going to be learning about sound. To begin, I’m going to give each of you a card. Look at your card and think about what in the picture might make a sound. Think of a word to describe the sound that you would hear.
Ask for a show of hands for each of these questions.
Who has an animal?
Who has a machine?
Who has a musical instrument?
Who has something else?
Many different things make sound. What causes these sounds?
Focus question: What causes sound?
Cup Investigation
When the din of plucked rubber bands reaches a level that suggests everyone is having success, call for attention. Call on a few students to report what kind of motion they observed.
Springing, bouncing, stretching, or wiggling motion
Buzzing, shaking, or tickling motion
Ask students to make more observations.
Look very closely at the rubber band when it is plucked to see how it moves.
Put the cup on your desk. Put your stick in the cup. Hold the cup on your desk and pluck the rubber band. Observe what happens to the stick.
Put your finger lightly on the rim of the cup right where the rubber band is. Pluck the rubber band to see how it feels on your fingertip.
Pluck the rubber band on the open top of the cup, on the side of the cup, and on the bottom of the cup. Does it sound the same in all of the locations?
Discussion
- What did it look like when you plucked the rubber band? [The rubber band moved back and forth really fast. It was blurry.]
- How did the stick sound when you plucked the rubber band? [The stick buzzed, bounced, and rattled. It was a small, fast movement.]
- How did the rubber band feel when you plucked it? [It tickled, buzzed, felt like electricity.]
VIBRATIONS...
TABLE FIDDLE
Have you ever seen a musical group with violins, bass fiddles, or even a banjo? The sound they make is beautiful music. What is vibrating when a bass fiddle makes a sound? Let’s find out.
Look at the table fiddle. The longest string will vibrate slowly. Invite a student to pluck the string to make a sound. Others should be able to see the string vibrating relatively slowly back and forth while the sound is audible.
Demonstrate that you can stop the sound by placing a hand on the string to stop the vibrations. When vibrations stop, sound stops.
Ask,
- How can I get the string to make a sound? [Pluck it to make it vibrate.]
- What will the string be doing while it is making a sound? [Vibrating.]
- How could I get it to stop making sound? [Stop the vibration.]
Invite students to touch the string gently after you or another student plucks the string. Have them confirm by touch that the string is vibrating.
Focus on cause and effect.
Ask,
- What is causing the string to make a sound? [Plucking it to make it vibrate.]
- What is the effect when I pluck the string? [Vibration and sound.]
Explain,
Cause and effect are important for us to think about when we work in science. They help us make sense of our observations so that we can test out new ideas.
Read “Vibrations and Sound”
- What do you see in the diagram?
- What are the different parts of this system?
- What are the fingers doing? What is the effect?
- What is the purpose of this diagram?
What does the author want us to know about vibrations and sound?
Where do we hear sounds? [Everywhere)
What is a sound source? [The thing that moves back and forth that makes the sound.]
What do you call the back-and-forth motion of strings? [Vibrations.]
What happens when you pluck a string on the table fiddle? [The string moves back and forth and makes a sound.]
Introduce the book fiddle
Show students how to make a smaller version of the table fiddle, using a hardcover book, two thick rubber bands, and a cup. They will need to find a book to use. They already have a plastic cup and one rubber band at their desks. Have them return to their tables to assemble and use a book fiddle to explore these questions.
- How can you get the book fiddle to make a sound? [Pluck the rubber band.]
- What will the rubber band be doing while it is making a sound? [Vibrating.]
- How could I get it to stop making sound? [Stop the vibration.]
The book fiddle is another way to investigate vibration and sound.
Show students how to insert a paper clip on the rubber bands and observe the paper clip when they pluck the strings. They will see the paper clip vibrate.
Review vibration and sound
Vibration is a kind of motion. It is a fast back-and-forth motion.
Objects that vibrate make sound. Sound always comes from a sound source that is vibrating.
Sound stops when vibration stops.
Some objects can be made to vibrate by plucking.
VOCABULARY
back-and-forth motion
observe
pluck
sound
sound source
vibrate
vibration
Introduce science notebooks
2.Open your notebook to page 4.
3.Write the date on the top of the page.
4. Glue on sheet.
What causes sound?
Sound is caused by _______. I know this because _______.”
Part #2:Hearing Sounds
Close your eyes and to listen carefully with their ears to hear a sound. Drop a coin on a table. Ask students to guess what common object made the sound.
Introduce Drop Chamber
Explain that students will be investigating the sounds that objects make when they are dropped onto the table surface. They will be dropping objects into a drop chamber to keep them from bouncing all over the place.
Demonstrate a drop chamber assembly so students see how it was made.
a.Make the large rectangle into a cylinder, using three paper fasteners.
b.Slide the vision barrier onto the top of the cylinder.
c.Position the chamber on a table between a pair of students.
Your first challenge is to become familiar with the sounds made by each of the objects in the set.
Go to the assembled drop chamber and demonstrate. Put one set of objects on one side of the chamber for one student and an identical set on the other side for the other student. Give them these directions.
a.Remove the objects from the bag.
b.Drop one object into the drop chamber and listen.
c.Retrieve the object by lifting the edge of the chamber.
d.Repeat with the other objects so students can hear each sound.
Drop Challenge:
a.One student selects an object and drops it into the drop chamber, being careful not to let the other student see it.
b.The second student identifies the object by its sound. He or she finds that object in his/her set and responds by dropping it into the chamber.
c.The pair of students should compare the sounds and decide whether the objects made the same sound. They lift the chamber, check if they were correct, and retrieve their objects.
d.The students change roles and repeat the activity.
Focus question: What kinds of sounds are easy to identify?
Demonstrate the tuning fork
This is a tuning fork.
- How can I get it to make a sound? [Drop it, hit it with something, hit it on something.]
- What will the tuning fork be doing while it is making a sound? [Vibrating.]
- How could I get it to stop making sound? [Stop the vibration.]
Hold up a wood block. Caution students that wood is the only object to use with the tuning fork. Holding the tuning fork by the handle, give it a smart rap on the wood block. Be sure to hit only one tine on the wood. To enhance the sound, put the butt of the handle firmly on a tabletop or other surface that will resonate with the vibrations of the tuning fork.
Demonstrate that the sound can be stopped by touching the tuning fork to stop the vibrations. Ask,
- Can you see the tuning fork vibrating when it is making sound? [No.]
- How could we confirm that the tuning fork is vibrating? [Try to make something else move with the sounding tuning fork.]
Demonstrate bringing the vibrating tuning fork gently up to an index card, a plastic cup, and other things suggested by students, to hear the buzz of the vibration.
Distribute table-tennis balls
Observations as students work at 3 centers
What to Look For
Students plan and carry out investigations with the tuning fork and other objects. (Planning and carrying out investigations.)
Students can explain that the cause of the sound is the vibrating tuning fork and that evidence of that vibration is when the tuning fork touches a piece of paper. (Constructing explanations; cause and effect.)
Students can explain that the cause of the sound is the vibrating tuning fork and that the bouncing table-tennis ball and splashing water are evidence of that vibration. (Constructing explanations; cause and effect.)
Demonstrate tuning fork and water
Bring a full cup of water forward. Tell students this is a subtle demonstration so they should get right near the cup to make close observations. Give a tuning fork a good tap and thrust the tips of the tines quickly into the cup of water. Students up close will get spritzed with a spray of tiny water droplets. Ask,
- What caused the water droplets to fly out of the cup? [The motion of the vibrating tines.]
- What caused the table-tennis ball to bounce away? [The motion of the vibrating tines pushed (applied a force to) the ball, making it move.]
Review vibration and sound
Vibration is a kind of motion. It is a fast back-and-forth motion.
- Objects that vibrate make sound. Sound always comes from a sound source (object) that is vibrating.
- Sound stops when vibration stops.
- Objects can be made to vibrate many different ways, including hitting, plucking, and dropping.
- Introduce the term sound receiver. Ask students to name what they use as a sound receiver. Confirm that their ears are sound receivers.
VOCABULARY
compare
ear
hear
identify
listen
property
sound receiver
tuning fork
Notebook
Distribute a copy of notebook sheet 2, Hearing Sounds, to each student. Ask students to review the focus question and to answer it in their notebooks. They might choose to write a sentence or two, or answer with one or more labeled illustrations.
- What kinds of sounds are easy to identify?
- How were you able to tell which object was in the drop chamber?
Look for these things in student responses:
Students say that loud sounds or sounds that vibrate for a while are easier to identify.
Students give examples such as knowing it was a coin that dropped because they have heard it before. Things made of metal make a ringing sound when they hit something hard.
Demonstrate tone generator
Introduce the tone generator as an electronic device that makes or generates sounds. Tell them that it is a sound source. Demonstrate how to turn it on and off and how to use the knobs to change the sound and to make the sound loud or soft (volume).
Ask,
- We are making a sound. What is vibrating? [Speaker cone.]
Ask students to gently feel the speaker cone to observe if it is vibrating.
- What is causing the grains to move? [The sound vibrations moving through the air from the speaker are causing the lid and the grains to move.]
The speaker is vibrating, and we are hearing a sound. The lid isn’t touching the vibrating speaker, but the grains of salt and rice are moving.
- How can you explain what is happening?
- What is the effect of the vibrations on the grains? [The effect is the grains move.]
Show students another way to observe the speaker vibrations. Place a few grains of rice and a pinch of salt in a container lid. Place the lid on the speaker cone. Dial up the sound (pitch) that makes the grains move actively. Then change the volume to show what happens.
When you reach a volume that makes the grains move very energetically, switch the tone generator off. Attach the lid to the surface of the wood block and use the block as a handle to position the lid about 1 cm above the speaker (not touching the speaker). Switch the sound generator back on and have students observe.
Confirm that the sound is moving through the air and making the lid vibrate. Vibrations cause sound, and sound can make objects vibrate.
Discuss it in terms of cause and effect.
Read “Listen to This”
- What do you notice about this photograph?
- What do you think the students are doing?
- Why do you think that?
- What are the parts of this model?
What is happening?
What do the curved red lines represent?
“Your ear is a sound receiver.”
Hmm, this seems like an important idea. I’m going to reread it and make sure I understand what it means. I think the diagram will help me. Someone is hitting the bell with a clapper, which is making the bell vibrate. The vibrations are traveling through the air to someone’s ear. This model makes me think of some questions. Share a question you have about the model with your partner.
What words describe the sound a lion makes?
How is the sound of a lion different from a cat?
How is the sound of a cat different from a kitten?
How can you tell if a dog is large or small by listening to its bark?
How are we able to observe sounds?
Part # 3: Outdoor Sounds
Have students close their eyes. Drop a pencil or pen on a table. Hide the pencil or pen and ask students to tell you what they heard. Once the object has been identified, ask,
- How did you know it was a pencil if your eyes were shut?
Explain that today students are going to go out to the schoolyard to listen for outdoor sounds.
Focus question: What information does sound give us?
Go outdoors
- Why do you think it might be important for us to sit silently? [So we don’t scare away any animals that might come by and so that we won’t miss any sounds.]
Once students are seated in appropriate spots, let them know that you are starting your timer. Give students about 5–8 minutes, depending on how successfully they are handling the task. Remind them to make a mental list of three sounds they would like to add to the class chart.
- What did you observe with your ears? What did you hear?
- Did you hear any animals?
- Did you hear a vehicle? Did you see it? (Do you think the vehicle you heard was big or small? Why?)
- Was that a loud or soft sound?
- What was vibrating?
- What information did you get from the sounds you heard
Call them back to a sharing circle. Ask some of these questions to prompt student thinking.
Notebooks
- Answer the focus question
- What information does sound give us?
Give students a couple of minutes to talk with a partner about their sound observations. For students who need scaffolding, provide a sentence frame such as “Outdoors I heard ________. The sounds told me that _______ .”
View online activity: “Sorting Sounds”
In small groups or as individuals, have students engage with the online activity “Sorting Sounds.” Students match sounds with words and images and sort sounds into groups, based on their properties. The link to this activity for teachers is in “Resources by Investigation” on FOSSweb.
Make a class list of sounds that words make.
Click Here: Sound Card Sort
Vocabulary
- Review vocabulary
Review key vocabulary developed in this investigation. Refer to the word wall for the list.
This is a good opportunity for students to make a concept map. Take key vocabulary words from this investigation and have students work in groups of four to make a concept map. For example, write the following words on self-stick notes so that each group has a set.
sound
vibration
sound source
sound receiver
hear
loud
soft
Review
- What causes sound? [A vibrating object.]
- Why is sound important in everyday life? [It helps us communicate with other people, warns us of danger, and helps us know what is going on around us.]
Music Extension
Show and tell about musical instruments
Have student musicians bring their instrument, or pictures of the instrument, to the classroom. Challenge students to figure out what is vibrating when the instrument is sounding.
Make a shaker from toilet paper roll.