Sound Travels

• Consider using a learning strategy such as Making Comparisons to support students’ development of the skill of observing.
• Educators may wish to:
  • pre-cut the string required for the spoon (30 cm lengths) and string telephone explorations (3 metre lengths)
  • poke a small hole in the center of the bottom of each cup
  • thread a piece of string through the cups
  • attach the ends of the strings to paperclips (to keep the string from slipping through the bottom of the cups)
     

Students use the Making Comparisons learning strategy to develop Comparing & Contrasting, Observing and Predicting skills as they learn about how sound travels.

Students:

• explore a collection of images of human and animal ears.
  • Educators engage with students during this exploration, noticing and naming what students observe and asking questions that provoke further development of the skills of observation and comparing and contrasting.
  • Educator works with students to consolidate observations (e.g., about the different ways ears are designed), prior knowledge, predictions (e.g., why animal ears look different from human ears) and theories (e.g., about how ears hear the sounds around us).

• describe what they see when they toss some pebbles into a bowl of water.
  • Educator works with students to consolidate observations (e.g., about how the surface of the water moves), prior knowledge (e.g., familiarity with water waves), predictions (e.g., the direction of movement of the waves from the point where the pebble enters the water) and theories (e.g., about why the water is moving in waves)

Students participate in the spoon on a string experiment:

• tie a piece of string to the middle of a metal spoon, allowing approximately 30 cm of string on either end.
• wrap the ends of the string around their index fingers, allowing the spoon to dangle in front of them.
• place their index fingers in their ears and tap the spoon against various surfaces in the room (e.g., the edge of a table, a soft pillow, a metal window frame, a drinking glass, a coat, the tile floor, an arm, a shoe) and describe the sounds.
  • Educator asks students to predict what the various objects will sound like (i.e., loud vs. soft sounds).
  • Educator asks students to compare and contrast the sounds from each surface.
• repeat, this time striking things more gently, and again with more force.
  • Educator asks students to predict what the various objects will sound like and compare to initial observations.
• describe and record their observations and compare and contrast them with the observations of other students.
  • Educator asks students to explain why they think they were able to hear sounds when they had their fingers in their ears.
• repeat the inquiry, this time cupping their hands over their ears instead of putting their fingers in their ears. Students record their observation.

Students participate in the string phone experiment: 

• compare and contrast the results with those of other inquiries.
  • Educator facilitates construction of string telephones if this was not done ahead of time.

• each student takes a cup and walks away from the person at the other end of the string until the string is straight and taut.
• predict what will happen when they take turns being the listener (cup to ear) and the speaker (talk into the cup, relatively quietly, but louder than a whisper).
• confirm their predictions, describing the quality of the sound (e.g., loud/soft, clear/fuzzy).
• repeat, letting the string go slack.
  • Educators ask students to predict how the results will be the same or different, and why they think that.
• repeat, staying the same distance apart and speaking at the same level but without the telephone.
  • Educators ask students to predict how the results will be the same or different, and why they think that.
• record what they observe and compare to their predictions and their previous observations.
  • Educators ask guiding questions to help students make conclusions based on information collected (e.g., air is not always the best transmitter of sound).

Observe and document, using anecdotal comments, photos and/or video recordings, student’s ability to:

• Predict – students predict how sound will travel through various materials and what will happen to the sound when variables of the telephone change.
• Observe – students observe and describe their observations.
• Compare & Contrast – students compare and contrast information gathered about how sound travels through different materials.
• Communicate – students explain their theories.
• Communicate - students use appropriate language to describe sounds and how they are produced.
• Draw Conclusions - students draw conclusions based on information collected during the experiments.

Literacy

• Ask questions (e.g., about why sounds are different, about how deaf people hear)
• Communicate thoughts, feelings and ideas (e.g., theorize about how sound travels, talk about sounds they like and don’t like)
• Use appropriate vocabulary (e.g., “The wave pattern in the water looks like when we skip stones in the pond.”; “I can see the string vibrating.”)

Mathematical Thinking

• Measure length using standard and/or non-standard units (e.g., measure different lengths of string for the string telephone)

Physical Education

• Identify the five senses and describe how each function, specifically hearing and sound

If your students are interested in learning more, the following may provoke their curiosity:

Repeat the string telephone inquiry with the following variations. In each case, students should make predictions, explain the reasons for their predictions, check their predictions and compare the results to previous inquiries.

• Have a third student hold on to the center of the string of the string telephone with his/her hand, to discover how this affects the sound.

“What happened when someone took hold of the string between the two cups? Was this you predicted? Why do you think that happened?”

• Have two pairs of students crisscross their strings, putting four telephones ‘on the line’.
  • “You predicted xxx would happen when we crossed two sets of telephone strings. Was your prediction accurate? Why/why not?”

• Reconstruct the telephone using longer or shorter pieces of string, and/or a different material instead of the string (e.g., fishing line, wool yarn).
  • “How did lengthening/shortening the string change the sound? Why do you think this happened?”

• How can you show someone who cannot hear what sounds are like? (e.g., how would you show a loud sound, a soft sound, a high sound, a low sound?) 

Design & Build a Musical Instrument (Lessons)

Students use their predicting skills to design and build a musical instrument that is able to change sounds.

What is sound and how do we hear it? (Backgrounders)

What exactly is sound, and how do we hear it?

Sound vs. Noise (STEM in Context)

What is the difference between sound and noise? How do they affect your hearing? And is noise always a bad thing?