When we stance on peak of a hill or in the midpoint of a extensive the bush amongst soaring trees and yell our name, your scream, after a short dally, is heard looping, although consecutively black out or reduce. This come back sound is an echo. An echo is a sound that returns to its origin like a boomerang.

So as to achieve come back in the guidance of its source, a sound or ray of light must either track down a path in space that is similar to of a parabola, return from a surface. An echo is the hindmost, it is a reflection of sound waves from article in the locality of the source.

The backscattering of sound is called echo. Echo is perceiving only when facade is far away. It is because the ears cannot differentiate between the two mouthpieces when sound is reflected from a close by surface. This occurrence is most commonly noticed on the hills. The echo is very transparent when on hills.

How is an echo perceived?

For a throwback sound to be perceived clearly, the sound must enchant a enough immensity and return after a certain detain. The delay is straight proportional to the breadth of the reflecting surface from the origin of the sound and the hearer.

Our hearing equipment is the pair of ears fond of to both sides of our head. Once a sound is discharged, the human ear cannot discern the recognize sound from the authentic if the setback is less than one-tenth of a second.

If the tempo of sound in air is roughly 340 m/s, then the total distance it travels, event and reflected, within this tapered window of 0.1 seconds, is 34 meters. This implicit that the barrier must be at least 17 meters aside for the reflected sound to be discernible from the occurrence sound and therefore perceived as an echo. When an echo come back in one second, the obstacle is 170 meters away. Likewise, it is 340 meters away when the echo come back in two seconds.