Did I make this happen or was this an upgrade you get? Probably 3-4 hours in the map on the gamepad started giving me a radar effect around my character where it makes a DING! noise every time there is a zombie nearby. Kind of like the Aliens sort of radar thing ya know? I'm not sure if I missed some dialogue or something from the Prepper saying he upgraded it.
Basically, I find it pretty annoying and can't figure out how to turn it off if I even can. Can you and how? It kind of hurts the game a bit too because I'll start hearing a bunch of dinging on my gamepad basically to tell me there are zombies around the corner. I liked not having it.