The loudest sound that’s ever been recorded was the explosion that came when the volcano Krakatoa erupted in 1883. You could hear it 3000 miles away and apparently the shockwave it sent out went round the world 7 times!
As for the loudest thing in the world today…well apparently the Blue Whale’s calls can be heard 100 miles away. It might not be the loudest thing in the world today (though I THINK it is) but it’s certainly the loudest animal.
Hope that’s okay. Some great questions in the Live Chat today by the way – good work 🙂