When a teacher loses attention from students, the usual response is to raise the voice and speak louder. The same kind of response is very common in marketing.
The problem is that the louder it is, the more people get used to it, the more it takes to be heard and the more people simply tune out.
The savvy teacher knows though, that to regain attention, lowering the voice is often a good trick. As well as telling something really thought-provoking, something that sparks interest, something that maybe even provokes an emotional response.
Marketers are well advised to use this trick too.