Sounds and Senses

In this lesson, students carry out a two-part investigation to explore how vibrating objects can cause sound and how sound can make matter (solids and liquids) vibrate. They use evidence to support an explanation about the cause- and-effect relationship between vibrations and sound.

• One animal behavior is making sounds to communicate with other animals. 
• We use our sense of hearing to hear different sounds, which are made by vibrating materials.
  
  

• What behaviors did students explore in the last unit?
• How can people make sounds? What are some examples of sounds?
• What do all of these sounds have in common?
• How can people use their senses to tell if something is vibrating? 
• Using a sound that’s been described, how could you do the same behavior but change the sound, either making it louder or softer?
• Why do we need ears to hear sounds? What would happen if we didn’t have ears? 
• How can hearing a sound change our behaviors?

Misconception: You see and hear an event at the same time.

Fact: You cannot hear sound until the vibrations travel from the source to your ears.

Misconception: A material’s vibrations are unrelated to the sound the material makes.

Fact: There is a cause-and-effect relationship between vibrations and sound. All sounds are caused by vibrations.

Ear: the part of the body that senses sound

Membrane: a thin, flexible covering

Sense:  how an animal gets information about the outside world

Vibrate: to move back and forth quickly

Vibrations and Sounds

All sound comes from vibrating materials. To vibrate means to move back and forth quickly. A cricket’s wings vibrate when they rub together.

Your throat vibrates when you talk. Feel your throat when you hum. It vibrates. This is how you make sound.

Sensing Sound

Your ears hear vibrations. An ear is the part of the body that senses sound. A sense is how an animal gets information about the outside world. Hearing is one sense.

A cricket has ears on its legs. You have ears on your head. When a cricket chirps, it makes vibrations. These vibrations move the air. That moving air reaches your ears. You hear the sound of chirping.

Crickets make sounds to communicate. They share information with other crickets. Other crickets listen. They hear the chirps.

As the main activity of this lesson, students carry out an investigation to explore how vibrating objects can cause sound and how sound can make matter (solids and liquids) vibrate. Students begin by using different materials and their senses to explore how vibrating objects can cause sound. Students then plan and carry out an investigation to help them answer the focus question: “Can sound make sand and water vibrate?”