Merge pull request #11946 from Heroman3003/hearfix

Fixes vertical noise spread penetrating floors

code/_helpers/game.dm

@@ -249,13 +249,13 @@
 /mob/living/silicon/robot/can_hear_radio(var/list/hearturfs)
 	var/turf/T = get_turf(src)
 	var/obj/item/device/radio/borg/R = hearturfs[T] // this should be an assoc list of turf-to-radio
-	
+
 	// We heard it on our own radio? We use power for that.
 	if(istype(R) && R.myborg == src)
 		var/datum/robot_component/CO = get_component("radio")
 		if(!CO || !is_component_functioning("radio") || !cell_use_power(CO.active_usage))
 			return FALSE // Sorry, couldn't hear
-	
+
 	return R // radio, true, false, what's the difference
 
 /mob/observer/dead/can_hear_radio(var/list/hearturfs)
@@ -272,14 +272,17 @@
 
 	var/list/hear = dview(range,T,INVISIBILITY_MAXIMUM)
 	var/list/hearturfs = list()
-	
+
 	// Openspace visibility handling
 	// Below turfs we can see
 	for(var/turf/simulated/open/O in hear)
 		var/turf/U = GetBelow(O)
 		while(istype(U))
 			hearturfs |= U
-			U = GetBelow(U)
+			if(isopenspace(U))
+				U = GetBelow(U)
+			else
+				U = null
 
 	// Above us
 	var/above_range = range