What causes the horn sound itself on 2006 Ford Escape?

The horn sound itself in a 2006 Ford Escape is produced by an electric device called a horn relay. When you press the horn button on the steering wheel, it completes a circuit that sends electrical current from the battery to the horn relay. The horn relay then uses this current to operate an electromechanical switch that connects the battery to the horn speaker. This causes the horn speaker to vibrate, producing the horn sound.