“shofar.” The ram’s horn trumpet, not the metal trumpet.
“the wall of the city will fall down underneath itself.” This is a very literal rendering of the Hebrew text and a very real picture of what happened at Jericho. The excavations of Jericho both by Garstang in the 1920’s and Kenyon in the 1950’s show that the walls of Jericho were stone walls with a strong mud-brick wall on top of the stone wall. What happened in the destruction of Jericho was that the mud-brick wall collapsed and fell mainly on the outside of the stone wall and to the foot of it (thus “beneath” it), spreading out and up the stone wall and actually forming a kind of ramp up the stone wall. Thus, the text of Joshua is very accurate when it says that the people “will go up” and straight into the city. The Israelite warriors had to run “up” the newly formed mud-brick ramp, over the stone wall, and into the city, which they then conquered and burned.
“every man straight before him.” This is not “straight and level” but “straight ahead,” up and over the collapsed wall.