Eventually some spacefaring civilization will visit this system, note that the second and third planet are very similar and almost skip further exploration... But when they do, they'll be shocked to find out that one of the planets is a naturally developed hothouse hell while the other was turned that way by hapless inhabitants.
After we figure out how to increase the mass of our atmosphere 90-fold, maybe. Venus is around human body temperature at the altitude where atmospheric pressure is similar to Earth's.
Iirc, the second-most human-like is Saturn, where there are zones of warm air at around 10atms, which is manageable for humans. Not as radioactive as Jupiter, but you can't float a zepplin in pure Hydrogen. Also, the wind speed would obliterate any aircraft.
A chemistry professor that I was acquainted with did this as one of his lecture demonstrations. Shakhashiri (and he's still doing it - http://scifun.chem.wisc.edu/BZSPresentations/Presents.html Once Upon a Christmas Cheery, In the Lab of Shakhashiri is going on its 47th year!). https://www.youtube.com/watch?v=_tsgh_T59gE has what you are looking for (at 3:42 though you'll likely want to start a tad bit earlier).
Well, on Saturn thered be no oxygen to combust, so hot hydrogen could work, maybe (I'm suspicious that it would be able to lift the heat source much less the equipment). Hard part would be fuel to heat it.
Is there any reason to connect subsea methane releases to this kind of sound, or any human-audible sound? I was under the impression it gradual dissolution (where "gradual" is not to diminish its geologic speed).
It was nice knowing y'all.