Mysterious cold calls

Fogmatic

Had several of them, starting about 2 months ago. When I pick up the phone, there's a few seconds' silence. Then an obviously recorded female voice (possibly American) says 'Goodbye'. (So I hang up).

I'm posting out of curiosity, not for advice (my mind is suspicious enough to keep me fairly safe from giving details to people I haven't checked out first!).
I just wondered if anyone here has had calls like this, or knows how this presumed scam works?
I can't think of any reason for what I hear (unless they're only targeting the men, and it can distinguish between male & female voices?)

Del2005

Not too sure about the goodbye. Some companies use automated calling systems that dial your phone and when you answer connect you to the next available operator, which leads to couple of seconds delay. What you could be hearing is the operator who's lined up to talk to you saying goodbye to the last caller.

Hold the line for a bit longer and see if anyone then connects to you. They can't charge yet for receiving calls,yet, and you already know not to give information out.

Fogmatic

Thank you for your thoughts Del.

It gets curiouser and curiouser! An automated Goodbye? (Sounds like the identical recording every time. The tone is a bit 'Good riddance!').

I wondered about male/female targeting because of a scam we had a spate of once, about 'winning' a cruise. The call was apparently for me, but she wouldn't answer my questions until she'd spoken to my husband. Until he refused to give his credit card details and she abruptly gave up, I expect she was telling him how delighted his wife was about the cruise (being on a cruise ship isn't my cup of tea, and he knows it!).