The loudest sound ever heard on Earth was the eruption of Krakatoa in 1883. The Indonesian volcano ruptured the ear drums of sailors 40 miles away, and people 3,000 miles away reported it as “a distant roar of heavy guns.” To put that in perspective, it would be like sitting in Boston and hearing a noise that came all the way from Dublin. Source Source 2
Photo: Biblioteca Nacional de España, Flickr // CC BY-NC-ND 2.0
After the eruption, only one-third of the island survived.
A new volcano is active there today as seen in the video above.