Jan 24
When using a walkie-talkie in front of the wall on Gordion, there is a 3% chance every 40 seconds to hear a random "Wall sound".
There are currently two sounds that have a chance to play -- FreeRefillsForever.ogg and Kola.ogg, in order.
Unlike player voices, these sounds can be heard while not holding the walkie-talkie.
(Using a personally modded copy that plays a sound with a 100% chance every 60 seconds for the sake of recording. This is otherwise completely vanilla and you can find it yourself if you want to wait long enough.)