[O1111OOO]

> my question is more technical: how did the blot out the booing?

Filtering out boos doesn't seem to be an issue from a technical standpoint. It was done recently with Donald Trump at the US Open Tennis:

https://bimcmedia.com/booing-trump-at-the-us-open-tv-audienc...

"The USTA’s decision to comply with the White House’s wishes and shield Trump’s self-presentation from noise is hardly understandable. The British Guardian called it in tennis jargon an “unforced error” – a fault without necessity. The US Open are actually the Grand Slam tournament that cares least about etiquette."