Lesson 6: Sound waves

Question 1

What is the range of normal human hearing?

Answer 1

20Hz - 20kHz.

Question 2

What type of wave is a sound wave?

Answer 2

• Longitudinal wave.
• Sound waves travel through vibrations of particles.

Question 3

How is sound produced by a microphone?

Answer 3

• Sound wave (particles) hit a diaphragm (a wave disturbance/ different medium.)
• This causes the diaphragm to vibrate.
• Micro-phone then converts this into electrical signals.

Question 4

How is the sensation of sound caused in the human ear?

Answer 4

• Sound waves in the air enter the ear.
• The sound waves hit the ear drum
• The sound waves causes the ear drum and other parts of the inner ear to vibrate.
• This causes the sensation of sound.

Question 5

What medium can sound waves travel through? How do they travel through this medium?

Answer 5

• Sound waves can travel through solids.
• By causing vibrations in the solid.
• BUT THIS ONLY WORKS FOR A LIMITED RANGE OF FREQUENCIES.

Question 6

Why is the human hearing range limited to 20Hz - 20kHz?

Answer 6

• Frequencies outside of this range will not cause the ear drum to vibrate.
• Sound waves can only travel through solids (causing vibrations in solid) when the sound wave is at a certain frequency.

Question 7

What is a reflected sound wave called?

Answer 7

• A reflected sound wave is called “an echo.”

Question 8

True or False

Sound waves CAN travel through a vaccum.

Answer 8

• False.
• Sound waves can only move through a medium ie. air/ solid. That is because sound waves move by particles vibrating.
• In a vaccum, there are no particles that can vibrate.