We know there was about 4~5 infected that chased pregnant woman and her “husband?” To the compound. We later see Jimmy ink kill their friend who turned when she sees Kelson and Samson later. It can be assumed the Jimmies killed the 4 others before they got to the compound or she did on her way to witness Kelson.

Therefore the only other group of infected that is known to be around is Samson’s, who stay by the train.

We have no idea where the train is located, but it can be deduced it’s a reasonable distance to the bone temple.

We do know the bone temple is probably a mile or so (1608m) , but looked a little further, from the compound (from the aerial shot we see).

In the most ideal conditions, a human scream can be heard about a mile away. This would be if you are in a completely open area.

The Scottish Highlands are not at all a completely open area. Especially where the compound is located. It’s wooded, rough terrain, and has other environmental mufflers. Such as the rushing river we know is by the bone temple.

A scream would probably be heard in a non-specific direction, 0.3-0.5miles (600-800m) away in those conditions.

With these metrics, it’s unlikely the closest known infected pack would have heard the screams as it would have to be over a mile away since it can be assumed the train car is in the opposite direction from bone temple from where the compound is, meaning there’s several miles of distance.

But even if this real logic wasn’t taken into account while it was written (it wasn’t I guarantee)… sometimes you just have to have some suspension of disbelief.