1. A method for vocabulary integration in speech recognition, comprising: converting a plurality of speech signals into a plurality of words using a processor; applying a plurality of confidence scores to the plurality of words; receiving classification criteria for a primary application; classifying the plurality of words into a plurality of classifications to identify a vocabulary application group that the plurality of words belongs to by performing a first classification process based on using the classification criteria for the primary application and the confidence score for each one of the plurality of words; determining one or more unrecognized words of the plurality of words based on the plurality of classifications; receiving additional classification criteria for multiple secondary vocabulary applications for the one or more unrecognized words, wherein the multiple secondary vocabulary applications comprise application specific vocabularies; classifying each of the one or more unrecognized words to identify a vocabulary application group that the one or more unrecognized words belong to by performing a second classification process based on using the received additional classification criteria and confidence scores determined for the one or more unrecognized words; detecting a match for each of the one or more unrecognized words based on the classifying each of the one or more unrecognized words with the received additional classification criteria; and upon detecting a match for an unrecognized word, converting at least a portion of the plurality of speech signals corresponding to the unrecognized word into a plurality of recognized words.