1. A method of generating alternatives to words indicative of recognized speech, recognized based on input speech data, comprising: generating a reference path of recognized words based on the input speech data; receiving an operator selection input indicative of a selected portion of the recognized speech for which alternatives are to be generated; calculating boundary conditions for alternatives based on position bounds of a reference subpath corresponding to the selected portion of the recognized speech; and constructing from a hypothesis stores corresponding to the input speech data, alternate subpaths satisfying the boundary conditions.