My opinion: It's possible that if it were loud enough and could not be disabled quickly, a thief might abandon the attempt to steal it.
There would have to be four considerations:
a) very loud
b) cannot be switched off except with a key
c) would have to be in an extremely sturdy enclosure to prevent disabling, and,
d) would have to be very securely affixed to the bike's frame.
Nothing is absolute proof against stealing, but the aircraft cable lock is one the best because it's hard to cut off.
