1. A method for speech retrieval, comprising: detecting one or more coinciding segments for speech data by comparing a character string of a recognition result and a character string of a keyword, the keyword being designated by the character string and a phoneme string or a syllable string; calculating an evaluation value of each of the one or more coinciding segments using the phoneme string or the syllable string of the keyword to evaluate a phoneme string or a syllable string recognized in each of the one or more coinciding segments and that is a recognition result of phoneme speech recognition, wherein the phoneme string or the syllable string associated with each of the coinciding segments is a phoneme string or a syllable string associated with a segment in which a start and an end of the segment is expanded by a predetermined time; and outputting a segment in which the calculated evaluation value exceeds a predetermined threshold.