1> emotions - a jarred, ambiguous type is used to convey the fear and confusion in the womens voice.
2> enhance particular words - the most important words are bigger to illustrate his tone of voice.
3> personal charcteristics - there is a fuzzy halo around the words that i think demonstrate the mind of an old person and also as a conotation to religion and faith.
A variety of typefaces are also used to convey different people and different social situations. The positioning of the words also relate to the pace of the scenes and the words that are being said.