Loudest Sound Ever?

        "Technically the conditions prior to the Big Bang are undefined."

                  Factually: no one knows the Big Bang happened.

                         That's why it's referred to as a, "theory".
 
              ie: Hawkings works = Theoretical Cosmology/Physics.

https://www.newscientist.com/article/2053929-a-brief-history-of-stephen-hawking-a-legacy-of-paradox/ (RIP)

I was sitting one time in the front row at a Robin Tower concert ,I could hear after the concert....When I was young we would go to a concert and then take the NYC subway home both are really loud.Another time we were having lunch at my grandmother's house it was a ranch and the house next door blew ,and man that was loud.Gas explosion...

F22 Raptor sitting in place like helicopter, nose pointed straight up, wow!
Long term loud would have been Mitch Ryder & Detroit Wheels, standing directly in front of speaker stack, stoned and drunk.

Bassnectar show at Red Rocks 2017.. peaks at 110 dbs.. Made Red Rocks change their rules on volume and Bassnectar was banned for life.. 

Second loudest: 10 Billion Butterfly Sneezes...