Aparently 180 dB causes eardrum rupture and intense pain and thus is extremely deadly.
For comparison’s sake, Krakatoa volcano’s eruption was measured at around 183dB.
In: Biology
Sound waves will bounce when hitting an entity of significant different density. This is true for water and air. A lot of the sound energy actually will bounce off the air and stay in the water and vocal versa.
Try it when you are in a pool, can you hear voices when you are 6” below the surface.
Water and air have very different densities, so dB means a different thing underwater and in air. On top of that, dB underwater is measured differently – the reference point is 20 times quieter in water, which corresponds to dB levels that are 26 dB higher. Putting those effects together, [subtract 63 dB](https://fas.org/man/dod-101/sys/ship/acoustics.htm)*. Now you’re at 137 dB which is very loud, but not eardrum rupture loud. In other words, 200 dB underwater is the same acoustic energy per area as 137 dB in air.
Now if you’re outside in the air, sound has to travel from the water out in the air, which adds yet more inefficiency, due to the acoustic impedance mismatch between water and air. You’re going to lose about another 30 dB there, if you’re outside the water. Now you’re at 107 dB, which is like a stereo turned all the way up.
Further, sperm whales communicate by *clicking*. The actual sound lasts about 100 microseconds, or 0.0001 seconds. That’s very different from a sustained loud sound. For example, a popping balloon can go as high as 168 dB, but the actual balloon pop is an [extremely brief sound](https://www.youtube.com/watch?v=MyP7i1B_QNk) (what we normally think of as the sound of a balloon popping is actually all the echoing from the initial sound).
* Edit: I think 61.7 dB is closer to the real figure, but there’s some extra rounding error when the linked article splits it into two components and rounds to the nearest dB.
[deleted]
Krakatoa’s eruption was bit more louder than 183db.
About Krakatoa from wiki:
The eruption is estimated to have reached 310 dB, loud enough to be heard 5,000 kilometres (3,100 mi) away.[[7]](https://en.wikipedia.org/wiki/1883_eruption_of_Krakatoa#cite_note-winchester-7):248 It was so powerful that it ruptured the eardrums of sailors 64 km (40 miles) away on ships in the Sunda Strait,[[7]](https://en.wikipedia.org/wiki/1883_eruption_of_Krakatoa#cite_note-winchester-7):235 and caused a spike of more than 8.5 [kilopascals](https://en.wikipedia.org/wiki/Pascal_(unit)) (2.5 inHg) in pressure gauges 160 km (100 miles) away, attached to [gasometers](https://en.wikipedia.org/wiki/Gasometer) in the [Batavia](https://en.wikipedia.org/wiki/Batavia,_Dutch_East_Indies) gasworks, sending them off the scale .
Guess it was 183db in 160km away from krakatoa
Divers have talked about being “hit” by whale song at close ranges; the results are disorientation, partial paralysis, and body parts being numb for hours.
Found this years ago. I come back to it frequently. Here’s a sperm whale playfully turning divers inside out with clicks (not literally): https://youtu.be/zsDwFGz0Okg
Edit: there is a minute and a half of talking before an underwater video plays. Totally worth listening to the whole thing.
Also, turn your sound way up for that extra immersive experience.
Like someone said previously, 200dB in water is not the same as 200dB in air. But I heard stories from researchers: it does feel like your bones are shattering if the whale comes up to you and vocalizes at you. They’re probably thinking we’re too skinny to be in the water. 😂
Could they not just wear ear defenders?
Being 5 I guess you don’t understand that eardrum rupture and extreme pain are not automatically “extremely deadly”, or that “deadly” doesn’t get measured by any scale. Dead is dead. It’s always in it’s most extreme form.
Remember dB is a logarithmic scale so 183dB isn’t 3 less loud (to use a Spinal Tap reference) than 180dB, it’s half as loud.
Latest Answers