1. A computer-implemented method for simulating a run-time user interaction with a voice application, said method comprising the steps of: providing a simulation environment including a simulation tool coupled to a voice application; loading a user simulation script to the simulation tool; processing the user simulation script by the simulation tool to generate both a simulated input to the voice application and a simulated output from the voice application; wherein the simulation tool and user simulation script replace actual inputs provided by a live user, actual outputs provided by the voice application and all speech technologies needed when the voice application is not in the simulation environment, and wherein all actual interactions between the user and the voice application are represented by scripted text-equivalents that simulate both the content and execution time of such interactions.