Verbal Behavior: Extended Edition. Chapter 10: Supplementary Stimulation. Quote 27

The reinforcing effect of a clever style is hard to analyze; we usually simply report our delight and prove it by returning to the same writer for more of the same stimulation. But the laughter generated in verbal play is more objective. Laughs can be counted and even, as in a television audience, measured in decibels. (p. 285)