Franssen effect

Have you ever heard a cool sound when you hit a small object with a big object, like tapping a spoon on a glass cup? That's because the big object vibrates the small object, creating sound waves that travel to our ears.

Now imagine you have two big objects, like two drums, and you hit one drum with the same amount of force as the other. You might expect them to create the same amount of noise, but something interesting happens. The drum that you hit directly sounds louder to you than the other drum that you didn't hit directly.

This is called the Franssen effect. It happens because the sound waves created by the drum you hit directly reach your ears slightly faster than the sound waves created by the other drum, which bounce off walls and other objects in the room first. This difference in timing makes the directly hit drum sound louder.

So, even though both drums received the same amount of force, the Franssen effect makes one drum sound louder than the other. Neat, huh?