Also an Interviewing Technique?

By which I mean you give your subject the stone face as they talk and cease to take notes if you are using a reporter's notebook.

This is from Talking Points Memo.

As Senate Majority Leader Mitch McConnell’s (R-KY) relationship with President Donald Trump grew tense while the Senate struggled to pass a bill to repeal Obamacare, a frustrated McConnell would meet Trump’s mindless chatter on the phone with silence in an attempt to keep the President on topic, the Wall Street Journal reported Monday night, citing unnamed people familiar with the discussions.

McConnell would prepare for the calls with notes on health care, while Trump would try to begin conversations with unrelated banter, and McConnell simply stopped responding, per the Wall Street Journal: As it became clear Mr. McConnell couldn’t summon enough Republican votes to repeal the Affordable Care Act, the Senate majority leader stopped responding to the president’s chitchat, the people familiar said. 

 “Mitch?” the president said when Mr. McConnell fell silent in one call. “Are you there?” 

Mr. McConnell waited a beat, then responded. “Yes, Mr. President. Back to the bill,” according to those familiar with the talks.