Found: Lovecraft like story

In this horror story, a man is exploring a cave system and is in radio communication with his friend on the surface. He sends back messages about his progress as he descends further and further. He finds evidence of a lost civilization (I think) and strange creatures. He gets more and more frightened, and at the end of the story, one of the creatures speaks through the radio.

It is not the Beast in the Cave by H.P. Lovecraft.

>1 Trinity1198: It is not the Beast in the Cave by H.P. Lovecraft.

No, but is it maybe The Statement of Randolph Carter ?

https://en.wikisource.org/wiki/Weird_Tales/Volume_5/Issue_2/The_Statement_of_Ran...

Yes, that's it! I even found the audiobook version of it that had the super creepy voice at the end!

Thank you so much!!