'Horn' in the Bible

So Joab had a horn sounded, and all the people came to a stop, and gave up going after Israel and fighting them.

But Absalom at the same time sent watchers through all the tribes of Israel to say, At the sound of the horn you are to say, Absalom is king in Hebron.

And Joab had the horn sounded, and the people came back from going after Israel, for Joab kept them back.

Now by chance there was present a good-for-nothing person named Sheba, the son of Bichri, a Benjamite: and he, sounding the horn, said, We have no part in David, or any interest in the son of Jesse: let every man go to his tent, O Israel.

Then the woman in her wisdom had talk with all the town. And they had Sheba's head cut off and sent out to Joab. And he had the horn sounded, and sent them all away from the town, every man to his tent. And Joab went back to Jerusalem to the king.

My God, my Rock, in him will I put my faith; my breastplate, and the horn of my salvation, my high tower, and my safe place; my saviour, who keeps me safe from the violent man.