Physics · Class 9

Reflection of Sound and Echo

Sound travels in waves and bounces off hard surfaces just like light bounces off mirrors. When sound reflects back to us and we hear it again, that is

syllab.in · free

❓ Quick answer

What is an echo?

An echo is the sound heard again after it reflects off a hard surface such as a wall or hill and returns to the listener a short time after the original sound.

❓ Quick answer

What is the minimum distance needed to hear an echo?

To hear a distinct echo the reflecting surface must be at least about 17 metres away, so the reflected sound returns after at least 0.1 second (the persistence of hearing).

❓ Quick answer

What is the difference between an echo and reverberation?

An echo is a single, clearly separated repetition of sound. Reverberation is the persistence of sound caused by repeated reflections in a closed space such as a large hall, heard as a prolonged blur rather than a distinct repeat.

Learn it fully — free

Read the full Reflection of Sound and Echo explainer on Syllab

syllab.in

Open the full explainer