Question

State two conditions for the formation of an echo.

Answer 1

Echo

1. An echo is a reflection of sound that arrives at the listener with a delay after the direct sound.
2. The delay is proportional to the distance of the reflecting surface from the source and the listener.
3. Typical examples are the echo produced by the bottom of a well, by a building, or by the walls of an enclosed room and an empty room.
4. A true echo is a single reflection of the sound source. Some animals use echo for location sensing and navigation, such as cetaceans (dolphins and whales) and bats.

Conditions for echoes:

1. The minimum distance between the source of the sound and the reflector should be at least 17.2 m.
2. To hear a distinct echo, the interval between original and reflected sound must be 0.1 second.