I noticed that all the bombs/throwables do not atract zombies, they do play the noise when they land but zombies seem to not hear it, happens with vanilla and modded items, tested it in sp with only ATRO enabled, the issue happens with throwables from other mods also and only when ATRO is enabled.

Fire sometimes draws them towards the explosion, but the sound of the explosion of the throwable, like a pipebomb does not attract zombies at all, they dont seem to hear it.