1. A speech recognition system that recognizes speech data, the speech recognition system comprising: a speech recognition part that performs speech recognition of the speech data, and calculates a likelihood of the speech data with respect to a registered word that is pre-registered; a reliability judgment part that performs reliability judgment on the speech recognition based on the likelihood; and a judgment reference change processing part that changes a judgment reference for the reliability judgment, according to an utterance speed of the speech data.
1. A speech recognition system that recognizes speech data, the speech recognition system comprising: a speech recognition part that performs speech recognition of the speech data, and calculates a likelihood of the speech data with respect to a registered word that is pre-registered; a reliability judgment part that performs reliability judgment on the speech recognition based on the likelihood; and a judgment reference change processing part that changes a judgment reference for the reliability judgment, according to an utterance speed of the speech data. 2. The speech recognition system according to claim 1 , wherein the reliability judgment part performs the reliability judgment for judging the reliability of the speech recognition based on a comparison result between a likelihood difference judgment threshold and a likelihood difference that is a difference in the likelihood among a plurality of the registered words obtained as a result of the speech recognition, and the judgment reference change processing part changes the likelihood difference judgment threshold to be used for the reliability judgment to have a greater value, as the utterance speed becomes slower.