add sounds 'zap_on' and 'zap_off'

taken from
https://freesound.org/people/JustHallowed/sounds/691007/

mods/ITEMS/mcl_transmutation/init.lua

@@ -0,0 +1,49 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname)
+
+local exchange_node
+	function exchange_node(itemstack, placer, pointed_thing)
+		-- Use pointed node's on_rightclick function first, if present
+		local node = minetest.get_node(pointed_thing.under)
+		if placer and not placer:get_player_control().sneak then
+			if minetest.registered_nodes[node.name] and minetest.registered_nodes[node.name].on_rightclick then
+				return minetest.registered_nodes[node.name].on_rightclick(pointed_thing.under, node, placer, itemstack) or itemstack
+			end
+		end
+
+		-- Node exchange recipes
+		if node.name == "mcl_core:cobble" then
+			minetest.sound_play({name="zap_on", pos=pos, gain=1}, true)
+			minetest.set_node(pointed_thing.under, {name="mcl_deepslate:deepslate_cobbled"})
+        end
+
+		if node.name == "mcl_deepslate:deepslate_cobbled" then
+			minetest.sound_play({name="zap_off", pos=pos, gain=1}, true)
+			minetest.set_node(pointed_thing.under, {name="mcl_core:cobble"})
+        end
+
+
+		if node.name == "mcl_core:stone" then
+			minetest.set_node(pointed_thing.under, {name="mcl_deepslate:deepslate"})
+			minetest.sound_play({name="zap_on", pos=pos, gain=1}, true)            
+		end
+
+		if node.name == "mcl_deepslate:deepslate" then
+			minetest.set_node(pointed_thing.under, {name="mcl_core:stone"})
+			minetest.sound_play({name="zap_off", pos=pos, gain=1}, true)            
+		end
+
+
+		return itemstack
+	end
+
+--register Orb of Exchange
+minetest.register_tool("mcl_transmutation:orb_of_exchange", {
+	description = "Orb of Exchange",
+	inventory_image = "mcl_transmutation_orb_of_exchange.png",
+	wield_scale = wield_scale,
+	groups = { tool=1},
+	on_place = exchange_node,
+	sound = { breaks = "default_tool_breaks" },
+	_mcl_toollike_wield = true,
+	})

mods/ITEMS/mcl_transmutation/mod.conf

@@ -0,0 +1,5 @@
+name = mcl_transmutation
+depends = mcl_core,
+description = adds orb of exchange
+author = SmokeyDope
+title = Orb Of Exchange