POLARIS: Port's /tg/'s current sound.dm, plus pref

It's mostly the same, just a little more efficient. I added a 'preferences' var to pass a datum and decide whether or not to play the sound for that client based on some preference.

code/modules/mob/living/living.dm

@@ -1169,6 +1169,20 @@ default behaviour is:
 
 	item.throw_at(target, throw_range, item.throw_speed, src)
 
+/mob/living/get_sound_env(var/pressure_factor)
+	if (hallucination)
+		return PSYCHOTIC
+	else if (druggy)
+		return DRUGGED
+	else if (drowsyness)
+		return DIZZY
+	else if (confused)
+		return DIZZY
+	else if (sleeping)
+		return UNDERWATER
+	else
+		return ..()
+
 //Add an entry to overlays, assuming it exists
 /mob/living/proc/apply_hud(cache_index, var/image/I)
 	hud_list[cache_index] = I
@@ -1186,4 +1200,4 @@ default behaviour is:
 		return I
 
 /mob/living/proc/make_hud_overlays()
-	return
+	return

code/modules/mob/mob_helpers.dm

@@ -629,6 +629,13 @@ var/global/image/backplane
 
 	return TRUE
 
+/mob/proc/get_sound_env(var/pressure_factor)
+	if (pressure_factor < 0.5)
+		return SPACE
+	else
+		var/area/A = get_area(src)
+		return A.sound_env
+
 /mob/proc/position_hud_item(var/obj/item/item, var/slot)
 	if(!istype(hud_used) || !slot || !LAZYLEN(hud_used.slot_info))
 		return