I answered the call by saying nothing, after about 30 seconds the caller hung up.
Its a robo call that waits for a voice, if you say nothing it does nothing.
A real person would say something when the call is answered.
Received a call from 1-714-233-2137. CID was the phone number. I gave it the old one ring pickup and immediate hang up. I blocked the number after this call.
The trouble is they will call back with a different number, I get a dozens numbers from same scammers. Like the Viagra email, always a different address to block. Also was told if you lthem back, you may be billed for the call.
I downloaded the standard AT&T ring tone (it's three beeps followed by a message of 'you have reached a non working number.') I have it set up on my desktop computer and when I get a robo call, I use my hot key function which plays the tone and place my handset next to the speaker. If it is a computer calling, the robo caller listens for a busy tone, non working phone number, voice mail etc. I find the three beep non working phone response to be very effective.