It depends on the call, if it's a Robo-Call or phonebroadcaster, it's usually one ended where they contact you but fix it where the only way you can contact them is to call the number back and here the Long Pitch about their business.  And even then, it's next to impossible to talk to them.  So I usually just push the button to be removed from them contacting me.  The reason people do this today, ironically, is a Large Majority of people I find these days do NOT want to talk to Anyone.  Funny right?  But this is where your Greatest connections can happen with fellow Entrepreneurs.  So if on a Cold call, if someone is honest enough to make themselves accessible to talk, I love interacting with them and Great things have come out of those kind of conversations.  Good business collaborations or networking opportunities.  They may have something you need or vice versa.  I mainly on these calls look for ways to be of service and not try to be Served.  I genuinely want to see if there is something I can do to be of service.  That's my approach when someone cold calls me.