Merriam-Webster defines “stenographer” as follows: “A person employed chiefly to take and transcribe dictation.”
The White House employs several stenographers. Congress employs several stenographers. The Supreme Court employs several stenographers.
These takers of dictation cover hundreds of events for the U.S. government, and their transcripts almost always include remarks that can be heard from the attending audiences.
Though this is the norm and it has been for several years, there appeared to be some confusion Thursday morning for The Washington Post’s White House bureau chief.
We’re not sure what Philip Rucker is getting at in the following tweet, but it’s almost as if he is unfamiliar with basic stenographer practice:
The official White House transcript of Trump’s Warsaw speech includes six of these interruptions –> pic.twitter.com/G6GS0LrUrX
— Philip Rucker (@PhilipRucker) July 6, 2017
The above tweet is in reference to the official White House transcript of President Trump’s address Thursday in Warsaw.
The White House transcript does indeed note that the president’s Polish audience chanted his name throughout the speech.
Because that’s how this works. This isn’t some sort of recent development.
From the July 28, 2016, White House transcript of former President Barack Obama’s address at the Democratic National Convention:

From the Nov. 3, 2016, White House transcript of Obama’s address at a rally in Miami:

From the Feb. 28, 2014, White House transcript of Obama’s remarks at the DNC winter meeting:

There’s much more where this came from. You get the picture.
Stenographers take dictation, even at the White House. They write down everything that’s said as quickly and accurately as possible, and that includes even what is said by audiences (if it’s intelligible).
We’re not sure what the confusion is here or why it’s noteworthy that the White House transcript of Trump’s Poland address included the crowd’s chanting.
Stenographers: How do they work?
(h/t Jeryl Bier)