1. A voice processor comprising: a presenting unit configured to present text to an operator; a voice acquisition unit configured to acquire a voice of the operator reading aloud the text; an identifying unit configured to identify output intervals of phonemes included in the voice of the operator; a determination unit configured to determine whether each of time lengths of the output intervals is normal; a frequency acquisition unit configured to acquire frequency values respectively representing occurrence frequencies of contexts, respectively corresponding to the phonemes, the context including the phoneme and another phoneme adjacent to at least one side of the phoneme; and a score calculator configured to calculate a score representing correctness of the voice of the operator on the basis of the determination results of the time lengths of the output intervals and the frequency values of the contexts acquired respectively corresponding to the phonemes.