LEARN NC

Sound waves need to travel through a medium such as a solid, liquid, or gas. The sound waves move through each of these mediums by vibrating the molecules in the matter. The molecules in solids are packed very tightly. Liquids are not packed as tightly as solids. And gases are very loosely packed. The spacing of the molecules enables sound to travel much faster through a solid than a gas. Sound travels about four times faster and farther in water than it does in air. This is why whales can communicate over huge distances in the oceans. Sound waves travel about thirteen times faster in wood than air. They also travel faster on hotter days as the molecules bump into each other more often than when it is cold.

Learning outcomes

The students will:

  • identify mediums that sounds can travel through and classify them from slowest to fastest.
  • learn how whales communicate with sound through water (liquid).

Teacher planning

Time required

One 60-minute period

Materials needed

  • glass, plastic, and metal containers
  • various metal, wood, and string musical instruments
  • audio recordings of killer whales and humpback whales with corresponding sound spectrograms
    See the Learn More section in the sidebar for websites with audio recordings and spectrograms. You can use the Raven Lite software mentioned below to create sound spectrograms.
  • data table worksheets
  • science notebooks
  • optional: suction cup and microphone

Technology resources

Free Raven Lite software from the Cornell Lab of Ornithology. You can use this software to record, save, and visualize sounds as spectrograms and waveforms.

Activities

This lesson uses the 5E instructional model, which includes five phases: engage, explore, explain, elaborate, and evaluate.

Engage

Ask students if sound would travel better in solids, liquids, or gases. Have them share examples of when they heard things through the different mediums (air, bathtub or swimming pool, ear to a wall, etc.).

Have students demonstrate the three different states of matter and how a vibration would go through them. Divide students into three groups and quickly model the vibration traveling through the different states of matter. In the gas group, students stand far apart and it is difficult to pass, wiggle, or push along. In the liquid group, students stand close together but not super tight and it is easier. In the solids group, students are packed tightly and the vibration easily goes through all the molecule-kids.

Explore

Have students test how sound travels through solids. Students will work in pairs at their seats. One student will tap lightly on his/her desk and the second student will record what they hear through the air. The same person will tap lightly again while the second person lays his or her ear on the desk. The students should compare the sounds and record what they hear through the solid. Have the students try the experiment one last time, tapping louder, and, again, recording the results. Use a data table similar to the one below.

Example

Activity Sound Observations
Light taps heard through air (gas)
Light taps heard through table (solid)
Heavy taps heard through air (gas)
Heavy taps heard through table (solid)

Allow students to explore how sound travels through glass, plastic, and metal containers. After students have experimented for awhile, let them transition from these normal, everyday objects to musical instruments. The class will explore instruments of various mediums such as metal, wood, and string. Metallaphones, vibraslaps, cow bells, melody bells, and glockenspiels can be used to explore rapid, metallic vibrations. Various drums can be used to explore vibrations in wood instruments. Autoharp, guitar, or piano can be used to explore the vibrations of strings. By using these musical instruments to determine the tempo (speed) of the vibrations, students will discover which medium allows sound to travel the loudest and farthest.

Explain

Discuss how sound was much louder through the table than through the air. Ask students how they think sound would travel in a liquid. Accept reasonable responses.

Elaborate

Have students listen to sounds of killer whales and humpback whales. Discuss the whales’ habitat. Students should make some observations about the whale sounds related to pitch, duration, and volume. Replay the recordings so that students have time to represent the sounds pictorially in their science notebooks. After they have created their own representations, show the students spectrograms of the whale songs.

Students will express that how loud something is depends on how much energy went in to creating the sound. Loud sounds have large amplitudes and carry a lot of energy. Small sounds carry less energy. Engage students in a game of echo singing. The game may consist of words, sounds, or syllables. After echo singing a given pattern, students will take turns creating an improvisation of the pattern. Play the game together as a class. Then break into smaller groups of four to allow each student the opportunity to improvise and change the pattern of song like whales do.

Evaluate

Students should be evaluated based on teacher observation, participation, data table worksheets, and science notebook entries.

Extend

Using a suction cup, attach a microphone to the metal, glass, and plastic containers. Strike the object in some way and record the sound with the microphone. Use these recordings to create sound spectrograms in Raven Lite to allow students the opportunity to compare what they hear with what they see. If a microphone is unavailable a stethoscope may be substituted for listening.

Express how sound can be heard without ears. Profile deaf percussionist, Evelyn Glennie, who plays barefoot in order to feel the vibrations. You can see a video of her performing with the Sesame Street Grouchketeers on YouTube.

Research what different cultures used to make instruments. For example, the Inuit from the Arctic used whale bones.

Critical vocabulary

solid
is a certain size and shape
liquid
can flow, be poured, and spilled
gas
matter that has no shape or size of its own
vibrations
mechanical oscillations about an equilibrium point
pitch
the highness or lowness of a tone, as determined by the frequency of vibrations per second
duration
amount of time or a particular time interval
tempo
the speed of music
sound wave
audible acoustic waves

  • North Carolina Essential Standards
    • Music Education (2010)
      • Grade 5

        • 5.CR.1 Understand global, interdisciplinary, and 21st century connections with music. 5.CR.1.1 Understand how music has affected, and is reflected in, the culture, traditions, and history of the United States. 5.CR.1.2 Understand the relationships between...
      • Grade 6

        • 6.CR.1 Understand global, interdisciplinary, and 21st century connections with music. 6.CR.1.1 Understand music in relationship to the geography, history, and culture of world civilizations and societies from the beginning of human society to the emergence...
      • Science (2010)
        • 6.P.1 Understand the properties of waves and the wavelike property of energy in earthquakes, light and sound waves. 6.P.1.1 Compare the properties of waves to the wavelike property of energy in earthquakes, light and sound. 6.P.1.2 Explain the relationship...

North Carolina curriculum alignment

Music Education (2001)

Grade 4

  • Goal 8: The learner will understand relationships between music, the other arts, and content areas outside the arts.
    • Objective 8.01: Identify similarities and differences in the meanings of common terms used in dance, music, theatre arts, and visual arts including line, color, texture, form/shape, rhythm, pattern, mood/emotion, theme, and purpose.
    • Objective 8.02: Identify ways in which the principles and subject matter of other content areas taught in the school are related to those of music.

Grade 5

  • Goal 8: The learner will understand relationships between music, the other arts, and content areas outside the arts.
    • Objective 8.01: Identify similarities and differences in the meanings of common terms used in dance, music, theatre arts, and visual arts including line, color, texture, form/shape, rhythm, pattern, mood/emotion, theme, and purpose.
    • Objective 8.02: Identify ways in which the principles and subject matter of other content areas taught in the school are related to those of music.