4. The apparatus of claim 1 , wherein, for the extraction of the select frames, the processor is configured to extract the select frames according to one or more predetermined intervals to respectively intermittently extract frames from the first speech and generates the second speech using the extracted select frames so as be connected speech, and wherein, for the calculating of the acoustic score, the processor is configured to collectively provide the extracted select frames to the acoustic model as the connected speech in the second speech.
5. The apparatus of claim 4 , wherein the processor is further configured to generate the acoustic model by training the acoustic model using a set of first non-temporally contiguous speech frames, extracted by the processor from temporally contiguous speech frames of training data.