💯 An Echo as a Reflection of Sound Waves Explained with Clear Examples

📢 Receive Free Study Resources and Special Offers 🧲

Echo
An echo is an example of a reflected sound wave. If you clap your hands, they act like a point-like source of sound waves. These waves spread out, and some of them will bounce into obstacles.

Hearing an Echo
If the obstacle is distant enough, you can hear a delay between the original sound and its echo. The way our brains process sound makes it seem like the echo is coming from behind the obstacle.

Analysing Echoes
Computers can analyse echoes to calculate the distance to an obstacle. This is known as sound navigation and ranging (sonar). Sonar is often used to detect submerged objects, like sunken ships or submarines.

Question 1

What is an echo?

(A) A sound wave transmitted into a different medium.
(B) A sound wave reflected from the boundary between two media. ←
(C) A sound wave where the wavefronts are flat.
(D) A sound wave incident to another medium.

Whenever a wave reflects, it reflects because it has reached another medium. (Some of the waves is transmitted into the medium.)

Question 2

What does sonar stand for?

(A) Sonic Articulator
(B) Sound Navigation and Ranging ←
(C) Sonic Observation (Narrow Amplitude Range)
(D) Sound Output Nautical Reflection