APPLIED RADIOLOGICAL ANATOMY

Detailed explanation-1: -An echo is a sound that is repeated because the sound waves are reflected back. Sound waves can bounce off smooth, hard objects in the same way as a rubber ball bounces off the ground. Although the direction of the sound changes, the echo sounds the same as the original sound.

Detailed explanation-2: -When we shout in a large or vacant space, the sound is reflected back. Suppose you are standing in front of a high wall and clap your hand, you can hear the same sound of the clap back again. This is an echo.