1. An information retrieving apparatus comprising: a name database that registers at least one record as a unit, each of the record contains at least one attribute to be retrieved and a value associated with the attribute, wherein the value is content about each of the attribute; an operation input unit that receives an operation input of a user; a voice input unit that receives a voice input of the user; a voice recognizing unit that recognizes voice obtained from the voice input unit as a character string; a sound model storing unit that stores sound data referred by the voice recognizing unit; a language model storing unit that stores, as a language model, a vocabulary recognized by the voice recognizing unit and a connection rule of the corresponding vocabulary; a retrieving unit that retrieves the value of the attribute included in the name database using an input character string input from the operation input unit or the voice recognizing unit, and creates, as a candidate, the record in which the input character string is included in the value; an output unit that outputs, as the search result, the candidate of the record created by the retrieving unit; a selecting unit that selects the output candidate of the record; and a recognized vocabulary producing unit that receives a selection result of the record by the selecting unit, and produces a new additionally recognized vocabulary that is a voice recognized vocabulary to be added to the language model, wherein the recognized vocabulary producing unit records, in the name database or the language model, a corresponding relationship between the additionally recognized vocabulary corresponding to the input character string and the selected record.