@everetra- Yes, they’re loud. For that reason I would never retrofit them on cars and I would hate to hear them from other drivers as well.
Regular car horns are loud enough. We don’t need bullhorn versions of these instruments in automobiles. I think in alarm systems they would be more than appropriate however. The amplified, ear piercing blare is enough to send a signal to a thief that they’ve been busted and (hopefully) the police will be on their way.