A device extracts prosodic information including a power value from a speech data and an utterance section including a period with a power value equal to or larger than a threshold, from the speech data, divides the utterance section into each section in which a power value equal to or larger than another threshold, acquires phoneme sequence data for each divided speech data by phoneme recognition, generates clusters which is a set of the classified phoneme sequence data by clustering, calculates an evaluation value for each cluster, selects clusters for which the evaluation value is equal to or larger than a given value as candidate clusters, determines one of the phoneme sequence data from the phoneme sequence data constituting the cluster for each candidate cluster to be a representative phoneme sequence, and selects the divided speech data corresponding to the representative phoneme sequence as listening target speech data.