1. A method of operating a voice analysis system, comprising: using a front end interface on a computer system that includes a microphone to initialize a voice analysis system for a user by inputting at least a first voice recording of the user via the microphone to be communicated Over a network connection to a voice analysis computer system that analyzes and stores a template voiceprint for authentication of the user; using the front end interface to input a second voice recording of the user via the microphone and at least one parameter indicating whether the voice analysis computer system is to operate in a first speaker identification mode or a second word recognition mode to be communicated over the network connection to the voice analysis computer system; using the voice analysis computer system to analyze the second voice recording, setting voice analysis constraints to a first level if the parameter indicates the first speaker identification mode, or setting the voice analysis constraints to a word recognition second level if the parameter indicates the second mode; comparing the second voice recording to the template voiceprint, wherein the comparison is based at least in part on the constraints if the parameter indicates the first speaker identification mode, communicating over the communication network an indication of authentication of the user to at least one of the front end interface to authenticate the user on the computer system or a back end computer system to authenticate access to the back end computer system if the second voice recording provides a positive match with a voice characteristic of the voice template based on a stricter match requirement; and if the parameter indicates the second word recognition mode, communicating over the communication network to the front end interface a textual representation of the second voice recording if there is a positive match of words represented in the second voice recording based on a lower match requirement, wherein using the voice analysis computer system is used to analyze a plurality of second voice recordings and further comprises: storing a representation of each second voice recording as part of the template voiceprint for the user; if the parameter indicates the speaker identification first mode, then after there is the positive match and before communicating the indication of authentication of the user, using the voice analysis system to compare the second voice recording with each of the representations of each second voice recording stored as part of the template voiceprint for the user associated with the positive match to determine that the second voice recording has not been used previously for authentication of the user and communicating the indication of authentication of the user only if the second voice recording has not been used previously for authentication of the user.