When you drink a soda, it makes a snap and gulp sound which can alert nearby zombies. Up to how far can this sound be heard by them?
I have no idea what the actual distance is, but I have heard another player drink from at least 20m before.
Edit: Also each gun has an audible distance for zombies, but players can hear the gunshots MUCH further than the listed distances that will aggro zombies. I would not be surprised if you can hear another player eat/drink from further than zombies can hear it.