I don't say anything when I answer these calls, I just listen. Within 10 seconds I hear a double click and the line goes dead. That tells me for sure it was a robocall from some scammer. To bad some genius can't develop something in the way of a microwave sound that disables these jerk's phone system.
Called cell number, answered someone with one of those Mussie accents said some was down loaded on my computer. Told him he was not going to F&&kin scam me A&&hole he then hung up.