Question

What is an echo?

• A. Reflection of sound reaching to the listener some time after direct sound
• B. Reflection of sound reaching to the listener some time before direct sound
• C. Reflection of sound reaching to the listener with direct sound
• D. Depends on position of listener

Answer 1

The correct option is A

Reflection of sound reaching to the listener some time after direct sound

When we shout in front of any obstacle (cliff, wall etc.) the sound reflects from the obstacle and comes back. So we hear the sound twice, one is direct sound and the second one is the reflected sound. This reflected sound is known as an echo.

A reflected sound wave is always heard after the direct sound wave is heard. So, options B and C are incorrect.