1. A data process unit comprising: an acoustic space storing unit for storing an acoustic space composed of a plurality of first pattern models, which are generated from first speech data of a plurality of speakers, and each of which has first 4-dimensional or higher dimensional feature data; a speech data acquiring unit for acquiring second speech data of a target speaker; a position calculating unit for: converting the second speech data acquired by the speech data acquiring unit into second 4-dimensional or higher dimensional feature data; generating a second pattern model to correspond to the second speech data based on the second 4-dimensional or higher dimensional feature data; calculating a mathematical distance between the second pattern model and the first pattern models based on the second 4-dimensional or higher dimensional feature data and the first 4-dimensional or higher dimensional feature data; and calculating a position of the second speech data in the acoustic space based on the mathematical distance; a positional relationship information display unit for displaying information representing a positional relationship between the second speech data and the first pattern models in the acoustic space, on a two-dimensional plane or in a three-dimensional space with a relationship of the mathematical distance being maintained, based on the position of the second speech data; a speech data evaluating unit for evaluating a value of the second speech data as a higher value, as the number of first pattern models existing within a predetermined distance from the position of the second speech data unit becomes smaller; and an evaluation result display unit for displaying an evaluation result evaluated by the speech data evaluating unit.