Adds Earmuffs providing immunity to Changeling shriek (#14033)

* Adds Earmuff immunity to shriek

* Refactors hearing protection and adds deafness

* Update human.dm

* Removed implicit src

code/__DEFINES/mobs.dm

@@ -241,3 +241,9 @@
 #define is_admin(user)	(check_rights(R_ADMIN, 0, (user)) != 0)
 
 #define SLEEP_CHECK_DEATH(X) sleep(X); if(QDELETED(src) || stat == DEAD) return;
+
+// Hearing protection
+#define HEARING_PROTECTION_NONE	0
+#define HEARING_PROTECTION_MINOR	1
+#define HEARING_PROTECTION_MAJOR	2
+#define HEARING_PROTECTION_TOTAL	3

code/game/gamemodes/changeling/powers/shriek.dm

@@ -11,6 +11,10 @@
 /datum/action/changeling/resonant_shriek/sting_action(var/mob/user)
 	for(var/mob/living/M in get_mobs_in_view(4, user))
 		if(iscarbon(M))
+			if(ishuman(M))
+				var/mob/living/carbon/human/H = M
+				if(H.check_ear_prot() >= HEARING_PROTECTION_TOTAL)
+					continue
 			if(!M.mind || !M.mind.changeling)
 				M.MinimumDeafTicks(30)
 				M.AdjustConfused(20)

code/game/gamemodes/vampire/vampire_powers.dm

@@ -264,7 +264,7 @@
 			continue
 		if(ishuman(C))
 			var/mob/living/carbon/human/H = C
-			if(istype(H.l_ear, /obj/item/clothing/ears/earmuffs) || istype(H.r_ear, /obj/item/clothing/ears/earmuffs))
+			if(H.check_ear_prot() >= HEARING_PROTECTION_TOTAL)
 				continue
 		if(!affects(C))
 			continue

code/game/mecha/equipment/weapons/weapons.dm

@@ -209,7 +209,7 @@
 	for(var/mob/living/carbon/M in ohearers(6, chassis))
 		if(istype(M, /mob/living/carbon/human))
 			var/mob/living/carbon/human/H = M
-			if(istype(H.l_ear, /obj/item/clothing/ears/earmuffs) || istype(H.r_ear, /obj/item/clothing/ears/earmuffs))
+			if(H.check_ear_prot() >= HEARING_PROTECTION_TOTAL)
 				continue
 		to_chat(M, "<font color='red' size='7'>HONK</font>")
 		M.SetSleeping(0)

code/modules/mob/living/carbon/human/human.dm

@@ -254,7 +254,7 @@
 					limbs_affected -= 1
 				else valid_limbs -= processing_dismember
 
-			if(!istype(l_ear, /obj/item/clothing/ears/earmuffs) && !istype(r_ear, /obj/item/clothing/ears/earmuffs))
+			if(check_ear_prot() < HEARING_PROTECTION_TOTAL)
 				AdjustEarDamage(30, 120)
 			if(prob(70) && !shielded)
 				Paralyse(10)
@@ -278,7 +278,7 @@
 						limbs_affected -= 1
 					else valid_limbs -= processing_dismember
 
-			if(!istype(l_ear, /obj/item/clothing/ears/earmuffs) && !istype(r_ear, /obj/item/clothing/ears/earmuffs))
+			if(check_ear_prot() < HEARING_PROTECTION_TOTAL)
 				AdjustEarDamage(15, 60)
 			if(prob(50) && !shielded)
 				Paralyse(10)
@@ -931,12 +931,18 @@
 	return number
 
 /mob/living/carbon/human/check_ear_prot()
+	if(!can_hear())
+		return HEARING_PROTECTION_TOTAL
+	if(istype(l_ear, /obj/item/clothing/ears/earmuffs))
+		return HEARING_PROTECTION_TOTAL
+	if(istype(r_ear, /obj/item/clothing/ears/earmuffs))
+		return HEARING_PROTECTION_TOTAL
 	if(head && (head.flags & HEADBANGPROTECT))
-		return 1
+		return HEARING_PROTECTION_MINOR
 	if(l_ear && (l_ear.flags & EARBANGPROTECT))
-		return 1
+		return HEARING_PROTECTION_MINOR
 	if(r_ear && (r_ear.flags & EARBANGPROTECT))
-		return 1
+		return HEARING_PROTECTION_MINOR
 
 ///tintcheck()
 ///Checks eye covering items for visually impairing tinting, such as welding masks

code/modules/surgery/organs/vocal_cords.dm

@@ -157,7 +157,7 @@ GLOBAL_DATUM_INIT(multispin_words, /regex, regex("like a record baby"))
 		if(L.can_hear() && !L.null_rod_check() && L != owner && L.stat != DEAD)
 			if(ishuman(L))
 				var/mob/living/carbon/human/H = L
-				if(istype(H.l_ear, /obj/item/clothing/ears/earmuffs) || istype(H.r_ear, /obj/item/clothing/ears/earmuffs))
+				if(H.check_ear_prot() >= HEARING_PROTECTION_TOTAL)
 					continue
 			listeners += L