Prosodic Features

Intonation is referred to as a prosodic feature of English. This is the collective term used to describe variations in pitch, loudness, tempo, and rhythm. These features are all involved in intonation, stress, and rhythm.

Loudness has already been mentioned in relation to weak and strong syllables in English and in the extra prominence given to nuclear syllables. In more extended speech, loudness can be used for other effects. It is associated with anger (though anger can also be indicated by very quiet, tense speech). In public speaking, orators produce powerful effects by varying the loudness of their speech.

The pace of speech is called tempo. This too can be varied. Fast speech can convey urgency, whereas slower speech can be used for emphasis. Varying the tempo can also be used for effect in public speaking, often accompanying changes in loudness. When reading stories to children, we can vary the tempo and loudness to reinforce the meaning of the words.

Reference:http://englishonline.tki.org.nz