Following are a number of back-translations as well as a sample translation for translators of Isaiah 13:4:

• Kupsabiny: “Listen (plur.) to the noise that is on the hill,
  the noise from many people.
  The noise from groups that have gathered themselves.
  The God of power prepares the fighting men.” (Source: Kupsabiny Back Translation)
• Newari: “Listen to the sound of a loud roar on the mountain,
  the sound of crowds and crowds of people,
  and [of] nations and kingdoms gathering,
  it seems like an outcry.
  The LORD Almighty
  has brought together soldiers for war.” (Source: Newari Back Translation)
• Hiligaynon: “[You (plur.)] listen to the noise of so many people on the mountains. [You (plur.)] listen to the noise of the kingdoms and nations who are-gathering. The LORD Almighty is-gathering his soldiers for the battle.” (Source: Hiligaynon Back Translation)
• English: “Listen to the noise on the mountains,
  which is the noise of a huge army marching!
  It is the noise made by people of many people-groups shouting.
  The Commander of the armies of angels has summoned this army to gather together.” (Source: Translation for Translators)