The object of the present invention is to keep a high success rate in recognition with a low-volume of sound signal, without being affected by noise. The speech recognition system comprises a sound signal processor configured to acquire a sound signal, and to calculate a sound signal parameter based on the acquired sound signal; an electromyographic signal processor configured to acquire potentialchanges on a surface of the object as an electromyographic signal, and to calculate an electromyographic signal parameter based on the acquired electromyographic signal; an image information processorconfigured to acquire image information by taking an image of the object, and to calculate an image information parameter based on the acquired image information; a speech recognizer configured to re cognize a speech signal vocalized by the object, based on the sound signal parameter, the electromyographic signal parameter and the image information parameter; and a recognition result provider configured to provide a result recognized by the speech recognizer.