What is an Echo

In acoustics, Echo is a reflected sound. Reflection is the change in direction of waves when it hits an obstacle. The type of wave produced is completely dependent on the type of surface that the wave (sound wave) hits. Hence the echo varies with medium.

Production of Echo

Basically, an echo is produced when a sound wave strikes a surface perpendicular to it's source and bounces back just like when a ball hits a wall. The effect is that the speaker end up hearing what he has said again.

Uses of echo

Echo can be used for various purposes. Some of the uses of echo are :

• It can be used to measure the velocity of sound.
• It can be used to detect obstacles
• Echo is used to estimate the shape and size of an object.
• It can also be use to estimate the distance of an object.
• It can be used to estimate how fast an object is moving.

What is Reverberation?

Reverberation is the persistence of sound or echo after the source has been stopped. Reverberation is created when a sound or signal is reflected causing numerous reflections to build up and then less as the sound is absorbed by the surfaces of objects in the space such as furniture, people, and air.
Reverberation occurs naturally when a person sings, talks, or plays an acoustic instrument in a hall or performance space with sound-reflective surfaces.

Difference and similarities between Echo and Reverberation

Echo and Reverberation also called reverb are both products of sound reflection. They are two distinctive terms.
Reverberation occurs when a sound is reflected from an obstruction that is less than 15m or 50 feets away from the sound source or when the reflection sounds reaches the source within 50 to 100ms while and echo occurs when sound wave makes a round trip in more than 100ms or when the distance between the source and the obstruction is greater than 15m or 50 feets.

Reverberation occurs because the brain interprets a sound that is heard repeated within 100ms as a single note.