Hello how may I help you? What was the loudest recorded sound ever? That sound is a volcanic eruption that happened in 1888 What volcano was the sound from? It was from Mount Kratoa How many people were injured by hearing this sound? That is undocumented. However it is known is that several were injured by the volcano itself. Okay. How loud was the sound in decibels? It was about 200 decibels. Thank you for the great info You're welcome!