I love how he was clearly at least a bit shaken but "didn't find it particularly disruptive." I'd say Rep Cunningham did a really damned good job there, not that it's likely to matter much.

What he neglected to say, and would be important, is at 25% higher it is loud enough to cause permanent deafness, <50% higher, around 180, that's loud enough to kill a human. I wish he had asked the witness if he would sit for double the original volume, would that be disruptive? Now ask Trump.
16000 times louder....16000 times, when 2 times louder is well beyond the level that is deadly. Let that sink in. 8000 times louder than deadly. That's not only deafening for hundreds or thousands of miles in every direction (sound travels farther with less loss under water), it's undeniably deadly for miles....every time they ping it....to nearly everything. That level of sonic energy can shatter stone, what would one expect it to do to a tissue paper thin swim bladder?

I am astonished they're still trying this tech after the outrage at the hundreds or thousands of dolphins and whales it killed early on, years ago.

I think it kind of depends on what he means by 16,000x louder? If he's talking in decibels, then it's already a logarithmic scale, so 16,000x times higher output amplitude is about 84db? higher (which is no joke) not quite sure on the maths there. 16,000db higher is basically impossible unless we are talking a supernova or something.

That puts it at over 204db which is apparently the same volume as the Saturn V launch. Which would definitely kill you, but maybe not 8000 times over... I mean once really does the trick.

If he's talking about the energy input, it seems that's a different thing according to wikipedia, and would result in an increase of 42db, which puts it at 162db, which is about the same as a 12-guage.

He may also mean that the sound is that loud at source, but as the guy was probably trying to say as he was squirming, the distance matters. The sound energy will be dissipated over a 2D shell and so I'd guess it drops off proportional to distance squared plus some extra for loss as it goes.

All of that is in air, it's quite a different matter in the water as I think the force is transmitted more efficiently.

Either way, every 10 seconds for months? No thanks.

My guess was it refers to the energy involved, so "louder" is the wrong word. I had no idea under water and air decibels are completely different measurements. The science of underwater sound is convoluted and confusing.

https://dosits.org/science/sounds-in-the-sea/how-does-sound-in-air-differ-from-sound-in-water/

Why the ocean is getting louder
At 4:00 mark it talks about Seismic airguns . It indicate its about as loud as an jet take off and all the fish leave the area.

The ocean is getting louder because more people are dropping their cell phones overboard on cruise ships. No one can tell me different.

This is how we fulfill our responsibility to nature.
Humans deserve eradication as quickly and with as little collateral damage as possible.
Wanna fund my avian measles project? Ebolaids was a bust.

With just a hint of lavender so as to say, no hard feelings.

I know...I know....and all that leaking out of every orifice we will miss....but as I said, Ebolaids didn't work, the AIDS stopped the Ebola somehow.
Avian measlepox is showing promise....all the ooze and none of the treatability with the advantage of being spread by bird poop!