UNIFIED MESSAGING SYSTEM WITH VOICE MESSAGING AND TEXT MESSAGING USING TEXT-TO-SPEECH CONVERSION

A unified messaging system selectively provides voice messages and computer-generated speech messages to a set of subscribers. The unified messaging system includes a voice gateway server coupled to an electronics mail system and a private branch exchange (PBX). In addition, the unified messaging system is configured for determining if a received message is a text message from the electronic mail system or a voice message from the PBX. The voice gateway server preferably includes a trigraph analyzer. When a subscriber selects review of a received message that includes a text message, the trigraph analyzer sequentially examines 3-character combinations within the text message; determines occurrence frequencies for the character combinations; compares the occurrence frequencies with reference occurrence statistics modeled from text samples written in particular languages; and generates a language identifier and a likelihood value for the text message. Based upon the language identifier, a message inquiry unit selects an appropriate text-to-speech engine for converting the text message into computer-generated speech that is played to the subscriber.