There are a lot of things that are pretty loud. Being on stage or in the studio in the middle of a blast of feedback over your headphones or in-ears; playback during a crazy hip-hop session with the monitor control and subs on 10; standing next to the siren of a fire truck; the blast of a jet engine when you’re too close. Yep, these are all loud, but not the loudest sound on the planet.
NASA estimates that its loudest ever rocket launch was 202dB SPL, which probably qualified as the loudest – until now.
This was created by using SLAC’s Linac Coherent Light Source (LCLS) X-ray laser to blast tiny jets of water to create incredible sound pressures, and it all happened in 40 billionths of a second (The research was done in a vacuum as well, so no scientists had their hearing damaged in the process).
What’s more, 270dB is thought to be the loudest sound that will ever be created in the world as we know it. The reason why is that any more sound pressure would break apart the water molecules.
What about sound in the air? That has a theoretical limit of 194dB SPL for the same reason (can’t say how NASA measured their rocket to get a higher number).
Just for comparison, at 55dB we have the sound of normal conversations, an alarm clock hits 80dB, a chain saw 100dB, and a jet taking off 330 ft away is about 130dB. Some rock concert are reported to actually hit 150 decibels, although I’d like to see where they take their measurements to get this number.
The Krakatoa volcano eruption in 1883 supposedly produced a sound of 172dB recorded 100 miles away! The sound was heard in Dublin, over 3,000 miles from the volcano. That’s reportedly the loudest natural sound ever recorded (again, not sure how they measured that, especially in 1883).
But 270dB certainly seems to qualify as the loudest sound ever both now and going forward. And you thought your monitors were loud.