Analysis of a speech:

1) Aims of a speech (download)

2) Means and effects (download)

3) Elements of speech analysis (download)

4) What makes a speech effective? (download)

literary humour

verbal humour

(=something funny in the way of presenting/phrasing it).

It relies on the means by which the person, object or event is described, and is often dependent on the element of surprise.