Upon answering the caller will ask "Can you hear me?". Rumor has it that they record your voice saying "yes" and then use it to opt you into some sort of scheme that only requires verbal confirmation. I simply hung up without answering.

Don't answer!  Their first line is "Hello, can you hear me ok?"  Scammers.

Just called me, the lady said her name was Emily and she was having trouble with her head set and could I hear her. I hung up without saying anything else and immediately blocked the number.  The caller ID only said Jacksonville, Fl.

I had the exact experience verbatim.

Same thing do not answer, they try to get you to say yes