1. A method for creating a speech interface of a system with a computer, the method comprising: accessing, with the computer, a database that includes speech samples associated with any of a plurality of speech controls to the system; calculating a similarity indication between a first set of speech samples associated with a first attribute and a second set of speech samples associated with a second attribute; displaying the similarity indication between the first set and the second set; receiving analytical results of the displayed similarity indication and generating an electronic report of the analytical results; generating a language model regarding the first set based upon the speech samples included in the first set; and calculating a perplexity regarding the first set using the language model regarding the first set; wherein displaying the similarity indication includes displaying a graph where points corresponding to each of the plurality of speech controls are plotted so as to express the similarity indication and a circle is drawn, wherein the circle has one of the points as a center and indicates the perplexity for the speech control corresponding to the one of the points.