1. An information communication terminal configured to exchange at least speech information with a plurality of information communication terminals, comprising: a speech recognition module configured to recognize the speech information to identify a plurality of words based on the recognized speech information; a storage medium configured to store keyword extraction condition setting data in which conditions for extracting keywords are set; a keyword extraction module configured to read the keyword extraction condition setting data to extract a plurality of keywords from the plurality of words; a subject extraction processing module configured to: associate the plurality of words read by the keyword extraction module with knowledge network data in which the plurality of keywords and a route among the plurality of keywords are described in a network form, generate a plurality of word pairs in a predetermined order from the plurality of keywords, extract the shortest route connecting words in each word pair from the knowledge network data, give point values to each word on each of the shortest routes, count the point values given to the respective words, and extract a word having a relatively high point value as a subject word; a related information acquisition module configured to acquire related information related to the plurality of keywords; and a related information output module configured to provide the related information to a monitor.
9. The information communication terminal according to claim 1 , wherein the keyword extraction module further comprises: a different meaning word meaning determination module, including: a different meaning word determination section configured to determine whether or not the plurality of words include a homonym or a homographe, by using knowledge network data in which vocabulary information showing a correspondence between a vocabulary and a reading sound of the vocabulary and link information showing a distance relation of the vocabulary; and a meaning determination section configured to determine the meaning of the word having a different meaning, based on the distance between the plurality of words.