1. A speech recognition apparatus comprising a storage medium storing a relationship between a recognition reliability and a correct answer rate for every phoneme; and a processor programmed with instructions that, when executed, cause the processor to: receive speech; recognize phonemes of the speech and generate a first phoneme sequence representing corrected speech; match the first phoneme sequence with a second phoneme sequence representing original speech so as to create a pair of a first phoneme extracted from the first phoneme sequence and a second phoneme extracted from the second phoneme sequence; and replace the second phoneme with the first phoneme when the second phoneme differs from the first phoneme, a predetermined recognition reliability of the first phoneme is higher than a predetermined recognition reliability of the second phoneme, and a correct answer rate of the first phoneme determined based on the relationship stored in the storage medium is higher than a predetermined value.