An animal-horn wind instrument; a ram's horn is preferred for Rosh HaShanah in later tradition
In Scripture World English Bible
On the third day, when it was morning, there were thunders and lightnings, and a thick cloud on the mountain, and the sound of an exceedingly loud trumpet; and all the people who were in the camp trembled.
Then you shall sound the loud trumpet on the tenth day of the seventh month. On the Day of Atonement you shall sound the trumpet throughout all your land.
God has gone up with a shout, Yahweh with the sound of a trumpet.
It will happen in that day that a great trumpet will be blown; and those who were ready to perish in the land of Assyria, and those who were outcasts in the land of Egypt, shall come; and they will worship Yahweh in the holy mountain at Jerusalem.
