1. A speech recognition dictionary creating support device comprising: a speech data storage section configured to store speech data; a prosodic information extracting section configured to extract prosodic information including at least a speech power value from the speech data; a speech data dividing section configured to extract an utterance section in which a period with a power value equal to or larger than a predetermined threshold value lasting a preset time or longer, from the speech data based on the prosodic information, and to divide the utterance section into sections in each of which a power value equal to or larger than a predetermined threshold value continues for a given time or longer, to generate divided speech data; a phoneme sequence acquiring section configured to execute a phoneme recognition process on the divided speech data to acquire phoneme sequence data for each divided speech data; a clustering section configured to execute a clustering process on the phoneme sequence data to generate clusters each of which is a set of the classified phoneme sequence data; an evaluation value calculating section configured to calculate an evaluation value for each of the clusters based on the prosodic information for the divided speech data corresponding to the phoneme sequence data constituting the cluster; a candidate cluster selecting section configured to select clusters for which the evaluation value is equal to or larger than a given value, as candidate clusters; and a listening target data selecting section configured to determine one of the phoneme sequence data from the phoneme sequence data constituting the cluster for each of the candidate clusters to be a representative phoneme sequence and to select the divided speech data corresponding to the representative phoneme sequence, as listening target speech data.