The capability to view detailed events taking place inside of a speech search engine can be essential for reducing the computational complexity and enhancing the accuracy of a speech recognition system. This paper describes a generic search visualization and performance tuning tool, Vista, which permits a user to interactively examine data within the search module of a speech recognition system. Vista's key attributes include the ability to display a large number of active search paths simultaneously, to display data relevant to these paths, and to update the paths and data as the search progresses in time.