Forum:Clicking noise in Bioshock

So in the first Bioshock, when walking around sometimes I hear a clicking noise that starts slow, and I try to follow it, it seems to get faster when I get closer, but sometimes gets faster when I stay still when close to it (I think). I don't know what it is but it seems like it might be a timebomb because once the clicking is super fast there is eventually and explosion. Is this a timebomb or something that you need to get to?