Answer:The correct answer is "censor" and "censoring". In the text is stated that engineers have invented something that is able to censor offensive language on live television feed. That would be a "censor", an aparatous able to detect offensive language and "censoring" is the action that this censor does.
The author converts joy in the excerpt by using irony in the situation of it being so hot they have to fan themselves then, ironically they start singing a song titled heatwave