1. A method for simulating a run-time user interaction with a voice application, said method comprising the steps of: loading a user simulation script programmed to specify simulated voice interactions with the voice application; deriving from the voice application a nominal output of the voice application; and processing the user simulation script to generate both a simulated output for the voice application corresponding to the nominal output and a simulated input for the voice application corresponding to a pre-determined user input to the voice application.