12. The apparatus as claimed in claim 9 , wherein the speech recognition failure check unit comprises a speaking rate checker unit for estimating a speaking rate of an input speech signal, and determining whether the input speech signal is compatible with speech recognition by comparing the speaking rate of the input speech signal with a predetermined rate reference value.
9. The apparatus as claimed in claim 8 , further comprising: a speech recognition failure check unit for determining the plurality of speech recognition failures for the speech data and outputting the check results for the plurality of speech recognition failures.