6. A speech recognition method that recognizes vocabulary from a speech signal, the method comprising: generating a feature vector series that corresponds to the speech signal; recognizing, by a processor, a phoneme series corresponding to the feature vector series using a phoneme language model, which indicates connection relationships between phonemes and is modeled in consideration of a location where each of the phonemes is disposed in arbitrary vocabulary; and recognizing vocabulary that corresponds to the phoneme series, wherein the phoneme language model is the probability in the case in which one of a plurality of phonemes recognized at an arbitrary time is recognized in a state where previous (n−1) phonemes are recognized, with respect to each of the plurality of phonemes, wherein the recognizing of the vocabulary includes searching a comparison vocabulary having the maximum posterior probability with respect to the phoneme series on the basis of a vocabulary condition indicating a frequency of the arbitrary vocabulary, a comparison phoneme series obtained by subjecting the arbitrary vocabulary to pronunciation conversion, and an edition distance, wherein the recognizing of the vocabulary further includes recognizing the edition distance in a search space by each of phonemes of the comparison phoneme series and each of phonemes of the phoneme series.
7. The speech recognition method of claim 6 , wherein the recognizing of the vocabulary includes: dividing the comparison phoneme series into a plurality of continuous connection phonemes; dividing the phoneme series into a plurality of continuous connection phonemes; and recognizing the edition distance in a search space by each of the connection phonemes of the comparison phoneme series and each of the connection phonemes of the phoneme series.