Post #4959

📚📚📚📚 🖌 Facts and secrets 🖌 𝗪𝗛𝗬 𝗰𝗮𝗻 𝘄𝗲 𝗵𝗲𝗮𝗿 𝗮𝗻 𝗲𝗰𝗵𝗼 𝗼𝗻 𝘁𝗼𝗽 𝗼𝗳 𝗮 𝗺𝗼𝘂𝗻𝘁𝗮𝗶𝗻 𝗯𝘂𝘁 𝗻𝗼𝘁 𝗶𝗻 𝗿𝗼𝗼𝗺𝘀❓ ✅When you stand on top of a hill amongst soaring trees and shout your name,after a short delay, is heard recursively, although successively fainted or dwindled. This returned sound is an echo. 📌For reflection of sound wave to take place the size of the reflector should be large So a mountain side and deep valleys are good reflector of sound for producing an echo.The reason that echoes aren’t heard in rooms is that the reflected sounds are received in less than 0.1 seconds, or the reflecting surfaces are at distances of less than 17 meters. Reverberations can also be heard in an empty apartment. . . .📒📕📘📗