1. A speech translation system comprising: a dictionary server; one or more speech recognition servers; one or more translation servers; and one or more speech synthesis servers; wherein each speech recognition server comprises: an information-for-speech-recognition storage unit capable of having stored therein information for speech recognition with respect to at least two of the two or more languages; an information-for-speech-recognition receiving unit that receives, from the dictionary server, information for speech recognition with respect to at least two of the two or more languages; an information-for-speech-recognition accumulation unit that accumulates the information for speech recognition received by the information-for-speech-recognition receiving unit in the information-for-speech-recognition storage unit; a speech information receiving unit that receives speech information that is information of speech input to a first terminal apparatus; a speech recognition unit that performs speech recognition on the speech information received by the speech information receiving unit by using information for speech recognition in the information-for-speech-recognition storage unit, and acquires a speech recognition result; and a speech recognition result sending unit that sends the speech recognition result; wherein the speech recognition unit of the speech recognition server comprises: a speech recognition determination section that determines whether speech recognition processing performed on the speech information received by the speech information receiving unit has succeeded or failed; a speech recognition information sending instruction section that issues, to the dictionary server, an instruction to send speech recognition information in a case where the speech recognition determination section has determined that the speech recognition processing has failed; and a speech recognition section that performs speech recognition on the speech information received by the speech information receiving unit by using information for speech recognition in the information-for-speech-recognition storage unit, and acquires a speech recognition result, and also performs speech recognition by using speech recognition information that the information-for-speech-recognition receiving unit has received from the dictionary server in response to sending of the instruction, and acquires a speech recognition result, the information-for-speech-recognition receiving unit receives the speech recognition information from the dictionary server in response to sending of the instruction, and the information for speech recognition accumulation unit accumulates the speech recognition information received by the information for speech recognition receiving unit after sending the instruction in the information for speech recognition storage unit.