Apparatus and methods for creating a composite data source having a common data representation from disparate sources of voice data. Data transmission links are established to heterogeneous messaging data sources, requests for voice data is sent using data access protocols, the voice data is received, and a set of voice data transformation rules are selectively applied to the voice data to transform the data into a common data representation. The common data representation can also be used as a source for reporting and graphical displays to monitor the operational aspects of the sources of voice data.