No hypotheses yet, but I found this fascinating. A bit long, but I thought it was worth reading. So much here I didn't know. I read this late at night and want to read it again, while fresh. So much info here and lots to dig on. Another while subject to capture my interest, lol. And tangentially related to my OP, I would guess. Thanks for your interest!

https://mysteriousuniverse.org/2014/11/strange-sounds-of-the-deep-dark-sea/

No hypotheses yet, but I found this fascinating. A bit long, but I thought it was worth reading. So much here I didn't know. Government set up listening devices in the ocean back in the 60s. Lots of sounds they can't make sense of. Some are possibly sea creatures, but others they have no idea about, particularly the rhythmic regularity of the sounds. I read this late at night and want to read it again, while fresh. So much info here and lots to dig on. Another while subject to capture my interest, lol. And tangentially related to my OP, I would guess. Thanks for your interest!

https://mysteriousuniverse.org/2014/11/strange-sounds-of-the-deep-dark-sea/