The sound of chariots and horses

2 Kings 6:24; 7:3-7 - Some time later, Ben-Hadad king of Aram mobilized his entire army and marched up and laid siege to Samaria.

Now there were four men with leprosy at the entrance of the city gate. They said to each other, "Why stay here until we die? If we say, 'We'll go into the city'-the famine is there, and we will die. And if we stay here, we will die. So let's go over to the camp of the Arameans and surrender. If they spare us, we live; if they kill us, then we die."

At dusk they got up and went to the camp of the Arameans. When they reached the edge of the camp, not a man was there, for the Lord had caused the Arameans to hear the sound of chariots and horses and a great army, so that they said to one another, "Look, the king of Israel has hired the Hittite and Egyptian kings to attack us!" So they got up and fled in the dusk and abandoned their tents and their horses and donkeys. They left the camp as it was and ran for their lives.

I wonder what (if any) natural phenomenon God used to replicate "the sound of chariots and horses and a great army." An earthquake? Thunder? The wind? All of the above?

I wonder...How did the Arameans think the king of Israel had contacted and hired the Hittites and Egyptians, when all the time they had had the city under siege? I guess when you're very frightened, you don't always think logically.

I wonder how the men with leprosy got out of the city. Wasn't it locked up tight and heavily guarded so that no one could pass through the gates?