Sentence:  Experienced spielers know that, if they keep <WSD>rhubarbing</WSD> away in an unrelenting monotone, their audience will soon become hypnotised by the sound of the words and lose grasp of their meaning. 
Meaning of the word marked with <WSD> tags:  Of an actor in a film, stage play, etc.: to repeat the word "rhubarb" to create the sound of indistinct conversation; "hence", to converse indistinctly, to mumble.