In (Wright et al., 1997) phrase level significance was obtained for noisy transcribed data where the phrases are clustered and combined into finite state machines.
based on the hierarchical model described in Section 4 and topic identification mentioned in the last sub-section we describe  (1) a tool capable of aiding agents for efficient handling of calls to improve customer satisfaction as well as to reduce call handling time, (2) an administrative tool for agent appraisal and training.