Focusing the sound

Device description:

The exhibit consists of two dishes (antennas) facing each other and a few meters apart.


It turns out that when we are facing the antennas, we can talk to each other - even in a whisper. The sounds each of us make travel through space as sound waves. The antenna to which we are talking reflects the sound waves directed at it. These are then transmitted to a second antenna whose parabolic shape causes the re-reflected waves to be further focused. If our ears are placed in the place where the waves, which we call the focus, are concentrated, we hear an effectively amplified sound.
The participant's task is to communicate with another participant, using the phenomenon of sound focus.

How to perform an experiment?

Two people are required to perform this experiment. Stand by two parabolic antennas and try to talk facing each other. Then face "your" antennas and try to talk again.