Geophony is a big fancy word that means "sounds of the earth". When we talk about geophony, we're talking about all the different sounds that come from things like wind, rain, thunder, and even the quiet rustling of leaves in a tree.
You know how sometimes when you go outside, you can hear the wind blowing really hard, or the rain pouring down on the ground? Well, those are all examples of geophony!
It's just like when you're playing outside and you can hear the leaves crunching under your feet or the birds chirping. These sounds all come from the earth around us and they make up the big world of geophony!