[unfocused]

Is there also any truth to scammers calling you but not saying anything, in the hopes of recording your voice as you talk to train AI bots for future scams that use your voice? Or is that some urban legend/myth.

They are getting more and more creative.

[PlunderBunny]

Isn't it more likely that it's a call centre where each operator has multiple outgoing calls on the assumption that they will be on one call (on average) at any given time, but sometimes more than one call might be answered (e.g. they're still talking to another victim when you pick up the phone)?

[hyeonwho22]

I've gotten a few phone calls like that. A few years ago living abroad it seemed to be a targeted sales pitch for one gender (ex. makeup). Would hang up as soon as I answered, or pretend that they needed the number of my wife (I wasn't married).

More recently in the US I got a call where the other side didn't say anything and hung up after exactly one minute. Suspicious indeed.