Researchers at Duke University have developed metamaterials that can control sound waves with high efficiency. These materials, made from 3-D printed plastic, manipulate sound not through the material's properties but through their unique shapes and the spaces around them. The process is akin to how the pitch of a glass bottle changes with the amount of liquid inside. As sound waves travel through these structures, they resonate at different frequencies, affecting speed and direction. This technology could enhance sonar applications by controlling sound waves in water.

What is the primary factor that allows the metamaterials to control sound waves?

• The temperature of the environment

• The type of plastic used

• The color of the material

• The shape of the material

How do the metamaterials affect sound waves as they pass through?

• They change the color of the sound

• They alter the frequency and speed

• They increase the volume

• They make the sound inaudible

What analogy is used to explain the resonance of the metamaterials?

• A guitar string

• A tuning fork

• A glass bottle

• A drum

What is one potential application of these metamaterials in water?

• Reducing water pollution

• Increasing water temperature

• Enhancing underwater photography

• Improving sonar technology

What is the ultimate goal of the researchers with these metamaterials?

• To develop better soundproofing materials

• To change the color of sound waves

• To manipulate sound waves in water

• To create new musical instruments