Micah speaks to the people of Israel as if he were speaking to mountains that can hear him, so both instances of "listen" are plural. (See: [[rc://en/ta/man/jit/figs-apostrophe]])
Yahweh speaks as if he is in court and the mountains and hills are the judges. He commands the people of Israel to tell the judges why they have done what they did. (See: [[rc://en/ta/man/jit/figs-personification]])