Is there an echo when you walk in the alley at night?

Walking alone in the alley at night, besides your own footsteps, you will hear a "giggle" sound, as if someone is following him, which always makes people a little nervous, inexplicably nervous.

In fact, as long as you understand the scientific truth, you will no longer be suspicious. People will make footsteps when they walk on the ground, and the footsteps will touch the walls on both sides of the alley and bounce back like a ball, forming an echo. In broad daylight, people come and go, and the echoes are absorbed by the bodies of people coming and going, or drowned by the surrounding noise, and only simple footsteps can be heard.

In the dead of night, things are different. At this time, people walking in the alley can not only hear their own footsteps, but also clearly hear the echoes reflected from the walls on both sides of the alley. The alley is very narrow, and the echo of footsteps will continue to reflect after hitting the wall. The narrower the alley, the more times it is reflected. At this time, a series of "giggle" echoes can be heard, which is called trembling echo.

In our life, any phenomenon and thing contains certain scientific truth. As long as you are a conscientious person and use your head more, you will learn more scientific knowledge from your side.