1. A system for analyzing voice-based communication sessions, comprising: a player configured to replay a recording of a communication session; an analysis engine coupled to the player, the analysis engine configured to process a stored communication session to generate a result responsive to an utterance-of-interest in the stored communication session, wherein the analysis engine uses a language model specific to a speaker when an identity of the speaker is known; a presentor coupled to the analysis engine and configured to present a representation of the result; and a storage device coupled to the analysis engine, the storage device configured to cache a representation of the result, wherein the representation of the result comprises an indication of a match of the utterance-of-interest in the stored communication session and an indication of a certainty that the match is an actual match of the utterance-of-interest.