Originally Posted by zjs
I'm not debating the level of noise that they make; only the duration. I'm not convinced the noise would go on for long enough for a walker up several floors of a building to make its way towards the noise, when said noise is outside and involves negotiating corridors, stairs and doorways.
Andy is on his knees if you save him. You leave him when the walkers are about six feet away from him. Hard to believe he'd manage to get to Danny and cut him free in that time. If you kill Danny, he's still in the trap. The farm is a walk away, but it was a long walk nonetheless, and the walkers appeared very soon after the first shots.
Though this may be a bit late, the duration of the noise does not matter. It is revealed in the comic that they will follow the general direction of a noise long after it becomes quiet.